Restrictions to work in Thailand

If a European is offered a position in Thailand, what are the restrictions of obtaining a work permit? Are there any restrictions that would deny granting a permit based on country of origin, health status, previous criminal charges etc, as it is the case in most other countries?
What are the labor laws in general regarding expatriates working in the Kingdom, how strict are the rules?
Do Thai generally welcome foreigners as colleagues or is there a large resentment towards any foreign worker?
Thanks for any feedback.

Here is a site were you may find more info: Thailand Business and Legal Guide
Also do some looking around on this Forum: Thai Visa

If one is offered work, the employer should handle all the regulations.

The law basically makes it illegal to employ a foreigner in a position that can be filled by a Thai national with similar qualifications.

Although there are some work arounds, most firms would just as soon have a Thai who will work harder for less.