World of Warcraft leveling guides are designed to get your character to Level 80 as fast as possible. To do this, they get your character following a certain chain of quests that is designed to rack up experience rapidly. But each class has its own unique quests. Where do these fit into wow power leveling?
Each World of Warcraft class has attributes, abilities, and quests that make it unique. That's why you may love playing a Warlock, while you friend is big on Hunters, and so on. Just getting to Level 80 without developing the uniqueness of your character would take much of the fun out of the game.
So how does developing your character's unique attributes fit into the typical wow power leveling guide? It doesn't. It's a lot of work to integrate the unique quests for each class into a standardized leveling guide. Some guides just cover the basics of leveling and leave it up to you to figure out how to get your class quests taken care of. But that doesn't mean no one is doing it right.
Dugi's Ultimate World of Warcraft Guide and the Zygor Guides both include class quests in their leveling guides. When you use either of these guides, your character will automatically be guided to do relevant class quests as part of their progression from Level 1 to Level 80. This means that your character will be a fully-functional Hunter, Warlock, Druid, Death Knight, or whichever class when they're done blasting through the levels.