This is also the reason why when I read in WoW forums of people skipping guide sections, due to being too low level I'm not agree and start ranting about it: it'll be a mess syncronizing with the guide and I've seen many people complaining about missing quests or accusing the guide for being innacurate, but not realizing that was their fault since they're skipping and missing a lot of quest chain requirement. Of course this apply if you're following a guide, believe me, it's very frustrating when you remain stuck in a guide section due to the reasons I've mentioned, more than doing grey quests (but they allow to be perfectly in sync with the guide) and goiing here and there to get the pre-requisite quests.
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.
My second most anticipated new feature in the Tides of Vengeance update is the Battle for Darkshore Warfront. It’s the second cyclical battle between the Horde and Alliance, in which each faction takes turns gathering resources, fighting in a pitched raid battle and then controlling the Darkshore zone. In what I hope will be an improvement to the Warfronts feature, the controlling faction will gain access to diverse world quests in the zones they control, rather than the “kill x of y” quests from when it first launched.
Dark Iron dwarf - "Known for their fiery tempers and fierce determination, Dark Iron dwarves have a turbulent history with the other clans. A failed coup in Ironforge ignited the War of the Three Hammers, and many of the Dark Iron once fought in the service of Ragnaros the Firelord. Though one faction is pledged to Queen-Regent Moira Thaurissan, others refuse to stand alongside their kin. The Alliance seeks a united Dark Iron clan to harness the power of Azerite and aid their struggle against the Horde."
Azeroth paid a terrible price to end the apocalyptic march of the Legion's crusade—but even as the world's wounds are tended, it is the shattered trust between the Alliance and Horde that may prove the hardest to mend. In Battle for Azeroth, the fall of the Burning Legion sets off a series of disastrous incidents that reignites the conflict at the heart of the Warcraft saga. As a new age of warfare begins, Azeroth's heroes must set out on a journey to recruit new allies, race to claim the world's mightiest resources, and fight on several fronts to determine whether the Horde or Alliance will lead Azeroth into its uncertain future.
Do quests and complete the story of your first chosen area before returning to your capital to scrap all of the equipment items you acquired. You should be around Level 113 by the time you complete your first area. Before selecting your second zone, head to your faction hub ship to acquire your introductory quests to the mission table and your champions. Complete this introduction and then pick up the quest to establish your first foothold in enemy territory.
I do not recommend going for TBC, although I remember Hellfire peninsula to be decent, everything else is rather slow. Instead go for WotLK, Borean Thundra gets you levelled very fast, and then you can head straight for Icecrown at 67, which is also insanely fast, although admittedly has a few elite quests. You can go to Sholazar Basin alternatively. 2 zones should get you 60-80 no problem.