Early 2009 I cycled for a month in the Northwest of Thailand. Read my blog for this trip >HERE< , it also includes limited info on food, water and accommodation while cycling the “Mae hong son loop”.
I was going to write an article with other Thailand info but my poor memory means it would be outdated and inaccurate. Luckily my friends from www.tour.tk have written a very complete and detailed article about Thailand (and many other countries) including visa info and prices.
Check their Thailand info page out at http://www.tour.tk/country-information/thailand.htm
Pay attention to the new visa rules, its not a easy as it used to be.