Easiest way to get stuff done, is just to drop all quests and focus on one zone until you have done all (or most). One of the best resources on this site is
Crypt's guides, so read through the 45-60-parts and start gathering quests.
One of the better quests is "Stealing knowledge" (horde only, As far as I know), where you find four tablets in Azshara, give them to the quest-giver, then deliver the tablets to four people in Azshara, Orgrimmar, Thunder bluff and Undercity, and then finally deliver payment for said tablets to the original questgiver. It gives almost 30k and 6-7g for very little work.
Also, the "..of love and family"-questline is very nice. It has a good history attatched to it, and gives a good deal of XP. Unfortunately, the rewards aren't that fancy for warlocks, but one of the rewards sell for 7g or so, so it's not that bad.