[huyegn]

If you liked Kernighan and Ritchie's "The C Programming Language", then you'll love "Programming In Lua". The first edition is available online here:

http://www.lua.org/pil/

Like K&R, it's style is colloquially terse, yet each sentence is chock full of information. It's a great book for someone who's already coming from another language like Python.

If you're into graphics programming, then http://love2d.org/ would be the perfect vehicle for you to get into Lua while you read PIL.