Man, despite what some people have said, you CAN get a 3 month lease here, (i’ve done it 3 or 4 times) but it is harder and some places will refuse. Go to a zhong jie (real estate agent) but dont tell them you want 3 months. Look at a place, if you like it tell the agent that you want it but have some concerns (ie. I used to say noisy neighbours)but if its fine after 3 months, you’ll pay for another 3 after that (but dont put that on the contract!). Dont go to the big expensive places like Century 21, but just your average, dirty, semi-legal hole in the wall place (90% of real estate agents are like this in Chengdu). I was always reluctant to sign for 6 or 12 months cos i did have problems in the past (neighbours playing mahjong until 6 AM, rats, broken appliances)and like i said, some places will let you ahve 3 months.
Keep in mind that alot of fang dongs (landlords) arent even interested in earning too much rent; its basically an investment property to sell later. Also at this time of year there are lotsa vacant places, cos school year is over and students go home for spring festival or relocate in search of jobs.
The places and websites that cater to foreigners are ok if you have a high budget, but if you can speak some chinese, or have a chinese friend, i’d DIY. My old place was advertised on an english website for 600 kuai more than in a local shop, simply cos it was an english language site!
Good luck man!