This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The best advise I can give you regarding the API is to get the Java API documentation. You can find the Java SE 6 Documentation here: http://java.sun.com/javase/downloads/index.jsp Make sure to scroll down for that item, and click on the Download button to the right.
What you need to improve your understanding of the API is the API documentation, the Java compiler, and some time and patience.
All code in my posts, unless a source is explicitly mentioned, is my own.