What you need to do then is watch the Protection Warrior video, the Druid tanking rotation video, etc. Then check out the guides for each.
The main things you are probably interested in are things like talents and rotations.
Gearing shouldn't be much of a concern if what you say you need is true. The tanking classes tend to gear with the same philosophy in mind, regardless of class. Individual players have different ideas about how to gear, but that is more about personal choice than class needs. For example, there is no reason that class X should stack avoidance while class Y stacks stamina. There might be more benefit to class X stacking avoidance than if Y tries, but things like stamina versus avoidance are more of a philosophy in general rather than a class mechanics thing.
Start with the guides in this forum and its subforums:
TankSpot's Critical Guides & Articles Library - TankSpot
Protection Warrior video:
Druid Rotation video:
I don't know the DK guides as well, so I can't comment on those.