I will be moving up to Chiang Mai in December along with my girlfriend and son, the plan is to rent a place for a month whilst we house hunt to find a placeto rent for a few years. Basically wanting advice from anyone been through this, or just familiar with the potential short term rentals of some good options, basically just wanting a place that would be happy for monthly rental, internet, and good facilities.

Try Elegant Lanna guest house. They're on the internet. Free wi-fi, incl. pleasant breakfast, nice and quiet yet near Thae Pae gate, transport.

Green Hill is very nicely located and has a great pool...

http://www.greenhillplace.com/gallery.php

Thanks, nice places... will be checking them out.

I'm in the same situation with a little advance.

For research I found a monthly tenancy here:

http://www.hongpak.in.th/roomsmap. Prices are so low that I rented a second room for my furniture store.

And permanent housing for this one:

http://www.thaihometown.com .

Of course these sites are in Thai language but Anglophone websites prices are significantly higher and the quality of service is not to go. Also with our friend Google translation is no longer an obstacle.