I am often a little surprised at how often leveling guides and leveling advice is requested by readers. It's easy for those of us working on raids to forget what it's like for the new player, just starting out of Silvermoon or Mulgore for the first time. With the changes to the 1-to-60 game made with Cataclysm, it's never been easier to level. While Mists of Pandaria is bringing a whole new talent system, the 1-to-60 game is most likely not going to see another revamp, so we'll go forward assuming that getting to max level will take the same path. In order to discuss it, I went and rolled yet another warrior. It's for science, people.
For people rolling a new warrior, be it an alt or a new main, there is one thing I like to keep in mind: Know how you intend to level. Whether you're a new player or an old hand trying a warrior out, it's really helpful to know what you intend to do to get to max level. Each talent specialization is viable for questing and PvP (player vs. player), for instance, but if you're intending on tanking instances or flag running in WSG, protection is the clear winner. Arms may be the easiest to level, however, without the stress of tanking and fairly easy to gear up for.