[DownloadMan]

At the embassy you sign statuary declaration forms. These forms are proof that each person is single and free to marry, and are a mandatory requirement in registering a marriage in Thailand. Documents brought from overseas will not suffice. You need your passport and may be asked to provide proof that you are free to marry (such as legally divorced or widowed if married before).
These documents must be translated into Thai language by an authorized translator.

Then you need to take these documents to the legalization division ministry of foreign affairs (this apparently takes two to three days but the Ministry now offers an "express -service", which allows you to get the papers the same day, if you apply early morning. So this will speed up this process so far to 3-4 days.

After the Ministry of Foreign affairs has approved and verified all documents, you are free to go to any Amphur office (with a Thai interpreter) and this is where the legal marriage takes place. There they will register the marriage and give you the Thai wedding certificate , which you have to translate into your language and indorse again at your embassy. (Some countries, like the Dutch embassy require also the excerpt from the registry file and these to be endorsed again by the Thai Foreign ministry) Took a long search but I think I have finally got it alright.
When we got married I had an interpreter who ran the papers thru foreign office for us so we didnt have to fool with that, So good luck and hope you have along and happy life..