CoolLoong The only tutorial I can find is the old version of javacc(Maybe I didn't find it)
Somebody asked me a similar question a while back and the best answer I could give is that you should carefully go through the arithmetic example here and try to make sure you understand the example thoroughly.
If you have any problems with that -- general conceptual difficulties, issues about details, whatever... -- do NOT hesitate to come and ask any questions.
Right now, the documentation situation is rather poor. Actually, there is a lot of text written but it is very disorganized, maybe some of it is out of date and so on. We really need to get things more organized.
By the way, the wiki here is set to be publicly editable, so if you have anything that you can add that's useful, by all means, just start a page and start editing! Don't worry about saying anything inaccurate. We'll correct it if necessary!