Mahmoud, Q.H. (2000). "Distributed Programming with JAVA". Elliotte, R.H. (2000). "JAVA Network Programming" 2ed. Sridharan, S. (2000). "advanced Java networking" I like these, in the above order, assuming that you are new to network programming. There is a tutorial at Java.Sun.Com that introduces network programming adequately.
Tom Hennigan<P>Sun Certified Java 2 Platform Programmer