"I have no conection to this site I am listing nor do I list it for promotion value other than responding to the OP's request."
After deciding to retire in Thailand I to searched long and hard to find a place online that I could learn Thai. Several months went by and then I found this site. Here is what it states:
Welcome to thai-language.com, your Internet resource for learning the Thai language for over 15 years. Here you'll find 14301 audio clips, over 56155 dictionary entries, 826 images and illustrations, message boards, and a friendly world-wide community of folks who are interested in Thai language, culture, residency, and travel. This website provides information for English speakers with any level of interest—from beginners who wish to learn a few phrases before their vacation to advanced students who may be living, working, or retired in Thailand someday.
What I enjoy most about it is the audio feature so you can hear and mimic the sounds. Plus it is easy to navigate for first time users. Hope it's what your looking for:
http://www.thai-language.com/