[TUT] Do you want to learn coding

Lua 5.1 Manual:
http://www.lua.org/manual/5.1/

Lua Programming Reference / Examples:
http://www.lua.org/pil/index.html

Official Lua Wiki:
http://lua-users.org/wiki/
The wiki has tons of examples, snippets, libraries and such which can come in handy when working on in depth projects.

Official Lua Mailing List:
http://www.lua.org/lua-l.html

Official Lua Forums:
http://forum.luahub.com/
The forums are a bit less then used. The Lua community still uses their mailing list more than the forums.


Performance Tips and Tricks:
http://www.lua.org/gems/sample.pdf
http://lua-users.org/wiki/OptimisationTips
http://stackoverflow.com/questions/89523/lua-patterns-tips-and-tricks

Metatables; Learn them, love them, use them..
http://www.lua.org/pil/13.html
http://phrogz.net/lua/LearningLua_MetatableEvents.html
http://phrogz.net/lua/LearningLua_ValuesAndMetatables.html
http://www.dreamincode.net/forums/topic/175747-lua-metatables-tutorial/

Examples and Tutorials:
http://lua-users.org/wiki/SampleCode
http://lua-users.org/wiki/TutorialDirectory