In World of Warcraft, each character has a unique set of skills and abilities that define their role. For example, magicians –are powerful spell casters, who use supernatural forces to attack the enemy from a distance, but in the melee – are extremely vulnerable. These features determine magicians’ strategy: to keep their distance, do the most damage and hope to kill monsters before they get to them.
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.
Dugi’s leveling guide is the leveling addon I’ve always used to level as fast as possible. It will show you where to go and what to do in-game, speeding up the leveling process. This is optional though, as the game already does a pretty good job at showing you where to go at all times. The addon does, however, come with a couple of other nice features and perks.
As you're leveling, I generally recommend you just follow the natural flow of the progression through each zone. They're laid out fairly reasonably. But don't be afraid to hop around, especially if you're near a quest objective. You shouldn't actually need ALL of the zones listed to reach 62. Pick the ones you like best. It's much more important to simply be as focused as possible and flow from one quest to the next.
Picking up herbalism and mining is the best professions to have while leveling. Not only will you earn gold as you level, but you will also get extra XP. At level 20 you will get over 500 XP for picking up a ore or a herb while killing a mob only gives a little over 100 XP. Don’t go out of your way to pick herbs if you are trying to level quickly, but pick the ones that are on your way. Leveling from 110 to 120 can be done pretty quickly just by doing this. There are a few items that will help you if you decide to use professions while leveling:

I would totally recommend using Zygor's if you are leveling alts or don't care about the quests you're doing, because it offers a huge leveling advantage in terms of streamlining what you do. Just let the arrow tell you what to do and you never have to think about where you're going or what you're doing. When I use this addon (and the leveling guides) I definitely understand why he charges for it.
And... that was it. New NPCs offered a glimpse of some truly amazing armor and weapons, none of which are currently available to players (and datamining suggests it may be a while, if ever, before they are.) There were no new appearances for players to farm, no items or pets or toys or titles to obtain, no achievements to complete. There was no repeatable, truly farmable content.
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.