You should consider what is available at the hotel. Does it have a pool? Do they charge for taking a guest with them? Are the prices higher in high season? Is breakfast included? Are there any special offers? Any mandatory holiday meals that I have to pay for (even if I don’t participate)?
Most hotels offer the basic bed, air conditioning, refrigerator, western bath/shower and cable/satellite TV. Some of the more expensive resorts offer room service and have one or more restaurants on the accommodation. If there is no restaurant at the hotel, don’t worry. There are many small restaurants and street vendors throughout the city.
I would then do a search and see if the hotel or resort has its own website and see what the prices are. Then I would check with one of the in-country booking websites and see if they have better deals (they usually do). Don’t worry, it’s safe and secure and the service is faster and better than dealing directly with the hotel.
After all, make sure you book your hotel or resort before you go. You don’t want to arrive and have no place to stay. And, book early if you plan to visit Thailand during the high season usually November to March. Pattaya resorts and hotels may also have higher prices during Christmas / New Year and during Songkran (Thai New Year mid April).