The best place to start is to..

- Pick a destination and research until you are happy with your decision (Trip Avisor .com is great for recommendations of hotels/resorts)
- Set a budget
- Pick a resort (or ceremony/reception location)
- Contact the resort's events coordinator

The rest will fall into place. The planner will likely have a questionairre which you and your DF can fill out together. It will include everything from the food, flowers, cake, decorations, ceremony etc. Once you have picked out the basics they will then go into more detail with you and before you know it - your wedding will be planned and all you have to do is show up!

Give me a yell if you have any questions - although I didn't get married in Thailand - I would say the process is the same with most destination weddings. You will need to check on the legalities of marrying in Thailand as every country has different legal and documention requirements.