it can be as cheap as 300 rmb per months for a really small apartment with just a bed and some basic furniture up to a couple of thousands. it also matters for how long you plan to live there, cause most landlords wouldn't want to rent it for just a couple of months, they would prefer at least half a year.

As for the websites, here are some: http://gl.58.com/chuzu/ ,   http://gl.ganji.com/fang1/

if you don't speak Chinese though, you would want some help from a Chinese friend.

Good luck!

Hi,
I hope my answer doesn't come too late, but I just rented an apartment in Guilin so I hope my experience is helpful. I blogged about it, but I'll give you a short version here.
_ if you don't speak and read Chinese, get help from a chinese friend. Few people speak good english in Guilin
_ the realy nice places are usually only rented for at least a year, maybe 6 months. You can still find a decent place for a few months though
_ talking about prices - you get what you pay for. RMB 1300 up should get you a very decent apartment, but you can find places for a few hundred RMBs too.
_ gas, water, electricity obviously depends on you. I made a downpayment of RMB 500 for the next 4 months and will settle the final bill when I move out.
_  if your budget isn't extremely tight, don't go for a place older than 10 years top.
Good luck and hope you'll have a good time in Guilin

I used 58.com, but had friends help me. My apartment was in my Gfs and my name, I think they utilities were also as I didn't ever know where to go to pay etc. My apartment was 2600, first ultility bill was over 600, I think it hadn't been paid before after that 100+.. I lived across from the bus station. I think everybody in Guilin knew where I lived, couldn't believe that.