Get yourself a good book, and start reading.
Here's an excellent one (in fact one of the very few really good books about it): http://www.bookpool.com/sm/0321349601

I have Deitel &Deitel book JAVA How to Program 6th edition happy with it. Also cover threads and I got more out of it then from my teach at university(he just love to complain about java)

The things taught about multithreading in non-dedicated books (and some dedicated books) are either overly simplified (often to the point of being dangerous when applied to real scenarios) or dead wrong (because the authors themselves didn't understand the topic).

As a result a lot of multithreaded code will work, usually, but only on a single CPU machine where there will never be multiple threads executing in parallel.
When run on a multicore or multiCPU machine they far more quickly run into trouble.

interesting I never thought of it. Yes we learn that mulithreading is design to speed up work especialy on multicore machines, but us non of has had chance to run pc with more then one cpu we don't give consideration to it. Will write to Santa get me new pc then...

Check the library, I just got a book from there and so far its pretty good.

"Java Threads, 3rd edition" - O'Reilly

It's overall pretty good (and I do have it), but I've heard that there are problems with parts of it.
You should IMO never rely on a single source of information anyway (easier said than done I know, especially if you're on a tight budget).

I happen to have a dual cpu athlon system, if what you say is true then I'll have to check that book out.

While on the subject of Threading, here's an article on hyper threading java for those interested. I saw it on javaworld a few weeks ago.

http://www.javaworld.com/javaworld/j...21-thread.html