My recommended steps:
- learn Lua first, you should try Lua references and Lua's twiki.  Feel free to to get a book if you like.
- once you are familiar with Lua, learning Lua should be simple.  DSLua is just Lua + DS-specific functions
- learn more about how DS works, should be in conjunction with the previous step

I really need to get myself in gear to write more DSLua documentations.  Right now, people are basically learning from the included sample scripts.

Waruwaru