I also recommend you grab the lua reference book. There is a version available on the website Bazzy posted. As Lua is heavily used in game development you can check out the forums at http://www.gamedev.net. There are forums specifically for lua and scripting.
Actually that site is just hard to follow, I found the actual tutorial tutorial for nubs on it. Much easier to follow than the API slash reference slash wiki guide slash "we never speak real english" slash Documentation slash thingy...