The Horde levels 50-60 guide has been rewritten and revamped.  My 1-60 Horde leveling guide is now completely updated for the 1.12 Drums of War patch.  As you can see it is about 15% larger than the 40-50 guide (single largest guide page yet).  There is also a lot of route changes.  I moved the entire Silithus section from level 55 to level 58, which allowed me to include a lot more quests for that zone.  There is also a lot of other improvement to the route, including adding a lot more quests into the guide, mostly from Moonglade, Silithus and Eastern Plaguelands.  This will make the final level 59 grind much shorter.
This kind of storytelling comes with problems, ones that players have been facing since the early days of the silent video game protagonist. Players in World of Warcraft have so much agency and choice when it comes to their own characters and how they build them. But despite their importance to the world itself, they can do nothing to change its story.
World of Warcraft: Battle for Azeroth focuses on the rivalry between the two most important factions of Azeroth, the Alliance and the Horde. The expansion adds two new continents (Zandalar and Kul TIras), divided into islands, where you can find new dungeons and raids, quests and previously unseen enemies, as well as six new playable races. Once again, the maximum experience level of the player characters increases (from 110 to 120). Battle for Azeroth also introduces two new game modes. In the first one, groups of three characters explore chosen maps and fight randomly assigned monsters and threats. In the other mode, groups of twenty characters each try to take over locations in strategic places for their factions.

At 98 you have the option to drop what you're doing and return to your capitol city to start the quest for your Legion Artifact weapon. However, I do not believe this is necessary to do right away unless you're struggling with kill speed in your current gear. I would recommend waiting for a natural pause, such as hearthing to repair and clear your bags. From 100 to 107 you won't even really fight mobs that often; only just enough to clear the way to any treasure you need to pick up.
These guides are completely automated and work in-game, so you can see step-by-step instructions as you play. The guides automatically move to a new step as you complete the quests. You are told where to go i.e. the questgivers for accepting and turning in quests along with where and how to complete the quests. Zygor has more steps and details, which would be more suited to beginners. Dugi condenses the info into fewer steps, but still has all the necessary questing info.
Professions: This may seem strange for a leveling guide, but the first opportunity you get, pick up both the Mining and Herbalism gathering professions. Not only will this allow you to track many various quest objectives on your map, but you also get a fair amount of experience whenever you gather. I'd put it at around 10% of a quest turn-in per gather. Since most of your wasted time in WoW is travel time, stopping to gather ore or herbs can keep your exp/h rolling as long as you don't go too far out of your way. You should only gather if it's convenient, and on the way to an actual quest objective. Don't make gathering your priority. 

Before anyone asks - yes there are archived copies of old addon versions both on our github repository and on several of the addon sites we use, and these will continue to be available after Cataclysm comes out, so you'll be able to get those old files if you really want them. I'm not going to bother making these more easily accessible unless you give me a very good reason. "I'm on a private server and I need them since we didn't upgrade to Cataclysm" is a BAD reason - and it's illegal.

Footholds into enemy territories can be done as you grow in levels and should be completed before reaching Level 120. Take the time after completing your first zone to do your first foothold, or you can choose to complete one as soon as you gather your 100 War Resources which will prompt you to return to your mission table area where the first foothold quest can be obtained. Similar to how your initial zone selection was largely irrelevant, this selection is, as well. Simply pick one and complete it to earn your Mission Table second champion. Send your champions out on missions, recruit troops, and then head back out to quest in your second zone selection.
Warlocks have received new spell effects; all the other classes received new effects in Legion. Male orcs are now able to toggle between the initial hunched posture and standing upright by using a barbershop, but the other races are not able to toggle between two postures.[5] There are new druid forms for the allied races, i.e. a Zandalari troll forms are all dinosaur-based, while the Kul Tiran humans take forms made of wood and bone as their teachings come from the Drust people who populated the land before them rather than the Cenarion Circle.
Both guides have a different look. Many players choose the Zygor guide because of the way it looks, with it’s modern, clean appearance. Zygor has improved it, so its easier to navigate. Dugi Guides interface blends into the game more, as it looks more like something you would find within World of Warcraft. It has icons down the right hand side for selecting your guides and is really easy to navigate.
I have tried it a few times. It's good if you're new to the game. Otherwise not so much. I found I leveled slower by using it, as it's suggesting to take the longest possible route usually. Basically following roads everytime, when you could take an easy shortcut. Especially if the shortcut involves a bit of fall damage, it's out of question. The "go here" spots don't also update if you take a shortcut, and then the waypoint arrow points to wrong direction. But perhaps it has been updated since then.
Alpha Beta PTR Classic 1.1.0 1.2.0 1.3.0 1.4.0 1.5.0 1.6.0 1.6.1 1.7.0 1.8.0 1.8.4 1.9.0 1.10.0 1.11.0 1.12.0 Burning Crusade 2.0.1 2.0.3 2.0.4 2.1.0 2.1.2 2.2.0 2.3.0 2.4.0 2.4.3 Wrath of the Lich King 3.0.2 3.0.3 3.0.8 3.1.0 3.2.0 3.2.2 3.3.0 3.3.3 Cataclysm 4.0.1 4.0.3a 4.0.6 4.1.0 4.2.0 4.2.2 4.3.0 4.3.2 Mists of Pandaria 5.0.4 5.0.5 5.1.0 5.2.0 5.3.0 5.4.0 5.4.7 Warlords of Draenor 6.0.2 6.0.3 6.1.0 6.2.0 Legion 7.0.3 7.1.0 7.1.5 7.2.0 7.2.5 7.3.0 7.3.5 Battle for Azeroth 8.0.1
Mythic+ has some similarity to raiding, but it’s designed for just five players, instead of the 10-to-30 that can make up a raid. This mode tasks players with clearing the game’s dungeons, but with specific changes that make them harder, scaling up until it’s impossible for groups to finish. Players receive a keystone in their inventory that assigns them their dungeon, one of the game’s 10, and gives the dungeon a level. This determines how difficult enemies are and what effects might make them harder. If the group completes the keystone in time, they get a new, higher-level stone; if they, don’t they get a lower-level stone.

It’s a good thing that the previous expansion, Legion, was the best in the game’s history because Battle for Azeroth is coasting on its success. The major class redesigns that happened then remain in effect (though some are a little worse, and some a little better), and the combination of World Quests and Mythic+ dungeons means there’s always something to do, no matter your skill level or how long you can play.

On January 30, 2018 Battle for Azeroth was made available for preorder, coming with the unlocking of the four first allied races. With the announcement of the Collector's Edition and release date for Battle for Azeroth on April 5, 2018,[3][5] Legion was the first expansion to be offered for free with a preorder.[6] Battle for Azeroth is the first expansion to launch in the Americas, Europe, Taiwan, Korea, and Australia/New Zealand at the same time.[1] Battle for Azeroth became the fastest-selling World of Warcraft expansion ever.[7]
Changes were also made to levelling in earlier content with Legion's 7.3.5 patch. The level-scaling tech introduced in Legion not only be continued in the new continents of Kul Tiras and Zandalar, but was also be applied to content from prior expansions, allowing larger level brackets for lower level zones. Further, as previous expansions are now included in the base game, the level ranges for those expansions are now broadened, allowing players to spend more time leveling in preferred expansions and avoid others entirely. Some examples include a zone like Westfall having its level bracket (at 10–15 as of Legion) increased to 10–60, whilst continents such as Outland and Northrend sharing a 60–80 level bracket. The aim of this change is to encourage more player choice whilst levelling and to allow players to experience the full story of a particular zone without overlevelling the relevant quests.
-Bugs- There aren't too many glaring bugs anymore, but you will certainly encounter some. The pathetic thing is that many of the bugs you'll encounter were reported repeatedly during Alpha/Beta and still weren't fixed. Some bugs were discovered after release and players were able to abuse game mechanics without repercussion unless they were one of the more serious offenders. This gave some players a significant advantage over others because they used exploits and at the start of an expansion, that is the time when it's most impactful.
A dungeon should take about half an hour to 45 minutes, that is reasonable. What did we do to Maw of Souls because it was by far the fastest dungeon to spam run for AP? Nerfed its yield. Same happened to dungeons. Except instead of nerfing the XP, they adjusted the clear speed to justify the experience a bit more. Is it perfect? Nah, a lot of dungeons aren't even that long with updates. At most a clear takes 5 mins more.
Download the game right now, create an account (a new one; not your old one, if you were a previous player), and you’ll be able to level your character all the way to 20 for free. There are other annoying limitations placed on this free experience, but it’s still a great way to familiarize yourself with the world, see if you enjoy the experience as much as you were hoping, and get a feel for the different classes before you settle on a main one to play as for the next 100 levels’ worth of gaming.
If you love running old content for transmog items, you'll love the new legacy loot system. Whenever a player enters a dungeon or raid where they are 10 or more levels above the content, the dungeon or raid bosses drop an amount of loot equivalent to what would have dropped for a full group when the content was current. That means players could earn loot for five people in dungeons and loot for 20 people after soloing a raid. The legacy loot system also drops other gear types, like cloth dropping for a plate wearer. It's now much easier to get the transmog gear you want, and you can also collect gear for your alts on the same run.