Just some tips :

1) No matter what spec you are (fury/arms/prot) - ALWAYS keep a set of each type of gears. i.e. Tanking set, DPS Set, Resist Set (if possible). As a DPS warrior you will still be required to off-tank during raids so it's good to brush up on that skill. As a DPS warrior you should be able to off-tank kara and heroics (with good healing love, and patient raid members of course). Holding aggro isn't a problem. Just let your team mates know you're NOT Prot and allow you some time to build aggro.

2) Get an aggro meter.... KTM Threatmeter i think it's called.

3) Leveling is much easier in Fury up till lvl 70. Do some speed leveling... don't spend so much time from lvl 61 - 69. The fun starts at 70.

4) Generally, Fury is perceived to give the most dps for raids. Arms are generally for PVP and Prot for tanking. You can mix roles so some degree of success though.

5) Get a good guild with nice matured people and friends.

6) PUGs aren't all bad. There are pretty decent skilled people in PUGs too that remain my friends/guildies till today.