The Internet has a LOT of Java material. The essential links for Java language study are the following:
Java development software (Sun's J2SE SDK)
Online help facility (Sun's J2SE API)
Official Java language specification
Tutorials from Sun Microsystems and Javaranch
Online forums at Javaranch
Becoming a Sun Certified Java Programmer
Of all the Java books on the market, the following are highly recommended:
Java 2: A Beginner's Guide by Hebert Schildt. An excellent introductory text if you are NOT interested in graphical programming.
Java 2: The Complete Reference, Fifth Edition by Hebert Schildt. An excellent all-around Java text covering introductory Java as well as graphical programming and other advanced topics.