If you are looking for websites on Java, there is one ultimate that you should bookmark right away: Sun's Java central. I don't think I can keep count on all of the times that I have typed their URL. It contains the API definitions, development tool downloads, developer and tech forums and of course many articles on the latest development.

For the slightly experience Java programmer, I can also recommend visiting Java World. I particularly like their many in-depth articles on many aspects of Java: Testing, using design patterns, performance tuning and much more. I personally subscribe to a couple of their newsletters.

As for books, there are an incredible number of Java books around! For beginners, I recommend Roger Garside & John Mariani's "Java: First Contact" which covers both the Java programming language as well as general aspects of object-oriented programming. Also, SAMS "Teach yourself Java in 21 days" and books of that sort can be handy.
Personally, I have half a shelf full with books on more specific Java topics: I/O, Servlets, Network Programming, Security, the Virtual Machine, ODBC etc. Nerdy bookstores are too big a temptation for me sometimes...