Bolshka:
A good tank will carry at least two sets of gear: tanking and DPS. At minimum a Warrior should always carry a shield. Initial focus on stats should be to build a set that raises your defense rating to 490 at level 70. Otherwise emphasis should be placed on Stamina, to the exclusion of socket bonus - having +12 stamina trumps the +3 parry rating or Strength a red gem might give you.
Your main-hand should be a swift weapon but in all things, +def and +stamina trump all. Your instant abilities as a Warrior will make up for a slow weapon if need-be.
Life after 490 Defense can be frustrating. Some people prefer to continue pushing the envelope to 500+ while others change gear around to maximize stamina. In my experience gearing for stamina seems the way to go, but even then I'm still well above 490.
Don't skimp out on socketing your equipment! Put rare-quality gems in anything that will last you a while (blue gear).
Don't skimp out on enchantments! Boar Speed on your boots, +threat on your gloves, clefthoof armor kit on the legs, +def inscription on the shoulders… all of these things add up to great tanking potential. It's well worth the cash spent!
