Hello Mahesh kara, welcome to CodeRanch.
First off all, you have a good OO
pattern concepts? How good you know java?
If you want to learn java there is a good
book named Head First Java. And another one to teach about the web Head First
Servlets & JSP.
Both books are very good to start with java.
If you want to get the certification, you can read the kate sierra book. It is a wonderful book.
c ya