I need a hint. I became leader of the thieves guild. I have done a few quests for the Jarl in Riften. What do I need to do to get a house in Riften?

http://www.uesp.net/wiki/Skyrim:Honeyside

you have to help citizens and the jarl.

Ok Geckoman. I shall try some more quests for them.

I'm 99% sure it's impossible until you've dealt with the skooma dealer issue.

Errmmm. Skooma issue? Where might this be found?

An Argonian woman. I ran into her outside the city by the stables but I believe she works down at the docks somewhere.

Walk around the docks and you should find her. She works in the fishing building.

Ok. I shall seek her out.

You must acheive CHIM first.

Then, you may buy a house, however, you will not need it.

Turn from your wicked ways and help clean up the city. Only then will they allow you to purchase a house.

Getting the house in Riften is bloody difficult and not all the misc quests initiated in that city count towards the number required. At the end got tired, cheated my way to it and replaced that stupid Jarl with Maven (she's an ass as well but at I got tired by the almighty righteous attitude of the former Jarl. That ipocrite two standards [censored] disgraced her son for speaking against Ulfric)

Ok, Shaen you are right. After dealing with the Slooma dealers, the Jarl let me buy a house.