Hi Maria.
For product related information, the best sources I 've got so far are the product manuals themselves.
In Windows/UNIX/Linux platform, you can find good info on Application Building Guide, Application Development Guide and Developing Enterprise Java Applications.
In the Mainframe you have the Application Programming Guide and Reference for Java, which covers installation, administration and even SQLJ.
In Java with DB2 you can use two API's for processing SQL:
JDBC and SQLJ. JDBC has dynamic SQL and as far as I can tell is the most used. SQLJ has static SQL (requires binding...) and you don't hear much about it.
Sun has a JDBC Learning Center web site
here.
For SQLJ reference look at the DB2 product manuals I suggested above.
Good luck.
