I am planning to move to CR in the next couple of months and want to find a nice, but small (read: cheap) house to rent. What is the best source of ads for this?

This link is a start:

http://classifieds.thaivisa.com/advanced_search/

Sometimes there are more listings, sometimes less. Check it each day for the newest.

Do a Google search for "Houses for rent Chiang Rai" The first three results give you a lot of opportunities to discover something you may like.

Come to town, rent a place by the week or by the day and stroll around downtown and the backstreets of downtown. Lots of places posted on boards, signs and posts in that area. There are some realty offices in that area as well and many of them offer rentals.

Go through some of the older posts here and you will find some posts by property owners and you'll find the same question has been asked and answered with a variety of helpful posts. ( TV search engine is available but Google you will get you there quicker if you choose the right words.)

You could contact Jeff at Lanna Realty in Chiang Rai. They deal in rentals as well as sales.

If you want a get a cheap but decent place (room/apt) for a month or two before you rent a house check out

Lalita Apartment, Memory Residence, or H&B Residence. H&B is 3,500 baht per month + utilities, and the other two are similarly priced.

here's some phone additional info on Lanna Realty and monthly rentals.

have u tried Thaivisa classifieds? .....Chiang Rai section