OK if you are going to be doing a lot of PVP at lvl 39 there are several things you could do.
If I were you and wanted to stay BM, I would mod your Spec to this
http://www.wowhead.com/?talent=cVbhzLxzZ0xZL or to this
http://www.wowhead.com/?talent=cibhzxxkV I would favor the first for pure PVP, as it has +5 to crit and an extra 4% to all tracked (humans) they'll drop like flies if you grab a better gun.
look over at Alla's gunlist to see what you want and how to get it ... i'd advise a Quest Gun that yeilds a lvl 37-39 gun (so you don't over level your battleground)
http://wow.allakhazam.com/db/itemlist.html?type=2.3&start=75
basic pvp strat at your lvl is basically send pet then just spam what you got about the same time pet gets there (if you let your pet first they won't auto target you *extra 1 second*) use frost traps to slow your opponents and run back and blast again. I'd stay away from the mana drain sting and stick purely to massive dps.
For Leveling, quest quest quest, use a Tank pet. to make things easier.
i'd spec this for leveling
(i went 10 lvls ahead so you can kinda see where my head is)
http://www.wowhead.com/?talent=cVbhzTgRVzhx and do quests that are appropriate to your lvl... again use Alla's zone info for lvl approproateness
Edited, Dec 16th 2008 1:17pm by Foxximo