If you are vegetarian or vegan and coming to Thailand don't expect vegetarian/vegan restaurants or culinary arts cooking school to be meat free just because they hang a vegetarian sign outside.
Very few, if any of the vegetarian/vegan Thailand restaurants are owned and operated and staffed by vegetarians or vegans as that’s just plain near impossible to do as there are virtually no Thai nationals that are vegetarian or vegan and speak English and work restaurants. This means when the vegetarian restaurant staff eat their meals there will be meat in the kitchen and on cutting boards and touching all related equipment.
Knowing this actually frees up vegetarians and vegans, while in Thailand, to select your meals from nearly any restaurant and select it by cleanliness not by signage,not by glossy website or brochure. Nearly every Thailand restaurant catering to foreigners will have an assortment of vegetarian/vegan dishes and no Thai restaurant will have the meat free container of equipment as required for a paid HappyCow.net listing.
You should also be aware of the fact that write ups in travel books such as lonely planet are near two years old when published making the information ancient history as business in Thailand goes. (i.e. business changes ownership and management between the interview, publication and your visiting two years later).
A travel site like Trip Advisor (T A) with free business listings and strictly enforced community review guidelines like a reviewer must be a site member and must have visited the site and must have partaken in the related activity in order to leave a review. T A has other guiding rules but the main issue here is relevance. T A reviews are as current as yesterday.
Also you should be aware of the fact that “organic” in Thailand is not organic as in organics being grown chemical free. Here in Thailand it references hydroponics and hydroponics are chemical fed and therefore are not organic!
Vegetarians and vegans, don’t be sucked in by slick promotion and slick websites and brochures. Just do a little homework, know the vegetarian vegan culture where you are going, then look for current information by way of T A or other quality information (non paid travel listing sites) with website review that has good control on who can leave reviews and you won’t be disappointed.
May your trip to Thailand be safe and wondrous!