• JDK 1.5.0 Top Level documentation and API documentation (javadoc)
• JDK 1.4.2 Top Level documentation and API documentation (javadoc)
• JDK 1.3.x Top Level documentation and API documentation (javadoc)
• How to set the Classpath [Solaris and Linux] [Win32] and How classes are found

• java.sun.com
• Java News and Resources @ Cafe au Lait
• XML Java News and Resources @ Cafe au Lait
• Searchable Open Source Mailing List Archives (includes jakarta - VERY useful)
• Sun Java Mailing List Archives
• JGuru FAQ and Javasoft FAQs

• JavaSoft Products

• Java Database Connectivity (JDBC) documentation and tutorial
• Tomcat servlet reference impl. and mailing list
• Java Native Interface (JNI) tutorial with book in pdf format
• Java Naming and Directory Interface (JNDI) tutorial and documentation
• Java Messaging Service (JMS) tutorial and SwiftMQ implementation

• Java 2D tutorial and Java 2D homepage
• Java 3D Community Site and tutorial
• Java MultiMedia Framework (JMF) and article
• Java Advanced Imaging (JAI) documentation

• Java 1.4 Security Guide
• Java Secure Socket (JSSE) Documentation
• Java Authentication & Authorisation (JAAS) documentation and tutorial and slides
• Java Cryptography (JCE) documentation and Handbook of Applied Cryptography

• Java Mail documentation
• Java Help documentation

• ibm.software.java.linux newsgroup
• Blackdown mailing lists

• Online Sun Java Tutorial - a step by step introduction for beginners into the world of object oriented programming and Java. It also contains detailed explanations to use many of the Java extensions such as Swing, JDBC, RMI, Servlets, etc.
• Java Precisely (a book in pdf format) gives a concise description of the Java programming language in 68 pages.
• Thinking in Java The second edition of a great pdf book
• Mini-Java Tutorial (SLAC)
• New To Java