At level 36, you shouldn't have to worry about tanking as opposed to dps for threat.
Sunder sunder sunder sunder....
If you can get away with it, and the healer doesn't mind, use a 2h and put on dps gear in defensive stance for threat. You can MS or BT (mortal strike, bloodthirst) in defensive stance.
Honestly, pre-bc I could tank up to zg (but not MT zg, just OT) spec'd fury.
Since your not expected to be wearing plate at 36, none of the mobs can hit that hard yet. And wont really hit hard until at least 55-60 where considering specing into more prot, and putting on more defensive oriented gear should be considered for instances.
DPS every trash mob down that you can.
I recommend sword and board for boss fights no matter the instance, if the boss is above or at your level.
Sunder, revenge, sunder, revenge...
Oforums good tank information guide.