If you know Java then you know Eclipse. Eclipse is an IDE which can make your life easier, it helps you when you compile, build and manage your project. It can help you with code completion and refactoring (renaming variables, etc.). It has also some plug-ins to connect to databases, design your GUI and deploy your application on webservers.
So just download Eclipse and start using it.
you can try using the book Java Programming. I used the 9th edition in my Programming Fundamentals college class. This is a good book, with definitions for all key Java terms, and gives step by step instructions for designing some Java codes. It also contains plenty of practice codes to try out, once you've gotten hold of the basics