I would refer you the book "A Programmer's Guide to Java Certification" by
Khalid A. Mughal and Rolf W.Rasmussen published by Addison Wsley,in this book
the author has completely explained the usage  of "this" key  word in a very good
manner ,it is one of the best Java books I have ever read, try to find this
book,if you still face problem than just mail me I will tell you the complete
usage.