Where I can found a good tutorial for JMonkey sound?
I'm afraid there is no such tutorial. 
Sound got somewhat neglected in jME. But there is basic support implemented…
Have a look at the sound tests for starting with it - then feel free to post here for help. And maybe put something in the Wiki when you have found things out 
the furballz src has a good sound manager documented a bit aswell but I don't know how up to date it is I wish it could be kept fresh in cvs like flagrush, furballs is the reason I figured out collision handling, now that flagrush might be on the shelf for a bit. there is a link in user showcase