There are many sources for information about Java. Sun Microsystems' official web site for Java topics is http://www.javasoft.com/. You should look here for the latest news, updates, and Java releases. This site is where you'll find the Java Development Kit ( JDK), which includes the compiler, the interpreter, and all of the classes in the Java API.
The various comp.lang.java.* newsgroups can be a good source of information about Java. The comp.lang.java.announce newsgroup is for announcements that may be of interest to Java developers. The comp.lang.java.api newsgroup is for discussion of the Java application programming interface; it's also a good place to ask intelligent questions. There are a number of other Java newsgroups for various kinds of specialized discussions. You should read the FAQ to find out more. The FAQ is maintained on the Web at http://sunsite.unc.edu/javafaq/javafaq.html.
Another large source of Java-related resources and Java code is http://www.gamelan.com/, also known as http://java.developer.com/.
You should also visit O'Reilly & Associates' Java site at http://www.ora.com/ publishing/java. There you'll find information about other books in O'Reilly's Java series.