Although we hear that in some of the offices of Thai department of Land transportation there are special counters for foreigners, where friendly government officers with a fair command of the english language help you to fill out these all Thai language forms, we strongly suggest that you always bring a translator / interpreter, when applying for a drivers licence.
Below is a scan of the application form which will be impossible to fill out without proper assistance and some of the officers that perform the color blindness-, depth perception- and reflex-tests may sometimes be looking for additional answers besides the standard: Red! Green! Yellow! etc.
The front of the driving licence application form.

The back of the driver's license application form

For everyone that has had any dealings with the Thai government this may not come as a surprise, but for those that have not: Do not print this file with the intention to use it as an actual application form. Any application, be it for a visa extension, a work permit application or whatever else, it will have to be written on an original which has been issued by the office one is applying to. We have, mistakenly, handed in perfectly good copies and those have always been filed in the trash bin. The thickness of the paper is, apparently, a big issue there.