There is a book on using Lua for Game Development from Apress that is due for publishing in early December. You can get an alpha release copy from Apress at http://www.apress.com/9781430246626
In case I forgot to mention, it is written by Jayant Varma (i.e. Me / OZApps) and portions of it have been Tech Reviewed by a couple of people who are well known on these forums. I can mention them once I get their permission to do so.