Any Thieve's Guild quest are given by Brynjolf, after that Vex and/or Devon. You won't get "Thieve Guild" quests from Maven, or her side kick.
Talk to Brynolf, if he's given you all your quests, than you'll need to talk to Vex or Devon. You may want to look over this walkthrough - http://elderscrolls.wikia.com/wiki/Thieves_Guild_(Skyrim)#Quests
As quoted in that article there are two bugs:
If you do not speak to Maven Black-Briar shortly after being given the quest, the quest will bug out and you will not be able to continue with the Thieves' Guild quest line. This is an issue as of 11/17/2011. (A not so elegant but effective solution is to open the console and enter the command "setstage TG04 1". That will allow you to skip the bugged quest entirely (if it′s not showing up for you) and continue with the Thieves Guild line). (confirmed 360 and PS3)
and
(known only for Xbox 360 and PC) To complete Thieves guild quest "Loud And Clear", you must talk to Brynjolf. Unfortunately, Brynjolf does not assign "Dampened Spirits" and there is no known fix to this bug, so save before talking to Brynjolf, try talking to him, and if it doesn't work load again and complete other quests until Bethesda fixes this bug.
I have to talk to Maven to start Dampened spirits, Brynjolf just says "sorry lad, I don't have time to talk right now". No other member of the Thieves Guild gives me the quest either. So I'm guessing I'm permanently locked out of the Thieves Guild quest line...