Hi Duran! Welcome to javaranch
I am afraid that the Study Guide for 5.0 will not explain Threading to you in more detail than the 6.0 book. If you are not clear about
thread basics, then you must read a book like Thinking in
Java or Java Complete Reference. That might help you grasp Threading better.
And also you can post what problem you are facing here, and there are a lot of people here that are willing to help everyone in any way they can. So you might get your confusions cleared here...