I'd say run steamvaults so you can get parts for the beastlord set, 2 pieces drop off the last boss. If steamvaults is too hard, i'd go for shattered halls, gloves drop off last guy. If you want a fairly easy, but nice leg drop, go into old hillsbrad. Some nice pants drop off one of the first few bosses i believe.
Also, i'd either buy http://wowhead.com/?item=31291 for fairly cheap, or drop murrmur (sp?), last boss in shadow labs, to get http://wowhead.com/?item=27903, or do a quest in the same instance area (can't rememeber what it's called) to get http://wowhead.com/?item=29329.
For a BM, i'd go with the axe first, easy to get, and better for BM then the quill. Sonic spear may be a bit tough for you to get at your current gear level.
And you can get a fairly cheap bow off of the AH (can't remember what it's called, but it's a blue 70, only one i've seen on AH, and it's there all time).
Getting the bow and the melee wep should help you do some quests (Netherstorm and Shadowmoon have good and fairly easy to get rewards), so you can get some better rewards to help make the instance runs a bit easier.
I personally still have a bit of this to do myself, but i have so little time playing on WoW i usually devote most of my time on my twink, but most of this stuff is pretty easy to accomplish.
Edited, Oct 11th 2007 8:05pm by FangXLR