1. Enchants are underestimated in pugs - they really need to enchant everything before stepping into pugs, including the DPS.
2. Do not assume because you're in 329, its doable, assume the worst, hope for the best. Every blue piece (enchanted) HELPS. If you can afford stuff off the AH, do it!
3. Use your crowd control no matter what - never AOE.
4. DPS and tank should sit and eat with you between pulls, no need to heal them.
5. Do not heal anyone over 75% during boss fights, except the tank, he should be your low-mana spam to keep your chakra up, with renew.
6. Gem for spirit, intellect first... forget haste and mastery for now. Reforge if you must.
7. Give it time for DPS and tanks to learn the fights and mechanics. Do your boss research.
8. Use lightwell, DPS use bandaids. Use Healing pots, mana pots, weeds, runes, whatever.
9. Melee DPS can be a good thing in pugs (2nd off tank to kite the adds) etc, don't lock yourself into 'typecasted rolls.' Even a moonkin can go heals when necessary. Don't be afraid to ask for back-up, especially at 329.
10. Give two hours per heroics at this time to learn the mechanics/fight of the game.
It will get better and easier for every piece of gear you get. Trust me.
Goodluck and have fun!
PS - RUN REGULARS UNTIL YOU'RE ALL IN BLUES --- the only green I had when I started was my wand, which I still have. Do the end quests in each zone, they give blue rewards, too.
Even better if you run up your rep to exhalted on a few factions for their exhalted pieces... do your research. Just because you're 85, does not mean you're heroic ready!