Have you decided where to go to? It really depends where you will specifically go in Thailand. Is it in Bangkok, Phuket, etc.?
Another thing to consider is the budget you are allotting for this trip and for the hotel. Perhaps you can consider getting a package tour and ask for options of good hotels out there. That is, if you have already decided where in Thailand.
I hope you can let us know so we can help you out further.
[ Edit: Edited on 01-Sep-2012, at 11:49 by D-Traveller ]