I want to start learning some L.U.A

Hello, my name is Luke and i have just started my Gcse’s, One of my subjects is Computing (Coding and seeing how computers work)
I want to learn some lua in advanced. My tutor is making a competition for a garrysmod gamemode, I just wondered if anyone knows any good websites to learn lua at.

Please never. ever. in your life write “L.U.A” or “LUA” again.

Also GMod lua is just like normal lua, you can start here http://lua-users.org/wiki/LuaTutorial
And here’s a live demo. http://www.lua.org/cgi-bin/demo

Also you can look here for GMod specific aspects: http://wiki.garrysmod.com/page/Category:Lua_Tutorials

Thanks for the help!