The google keywords I would choose for that question are: "java socket tutorial". Let's see what that comes up with... (googles...)
First link is a JavaWorld article:
http://www.javaworld.com/javaworld/jw-12-1996/jw-12-sockets.html... but it was written in 1996, so it's probably dated.
Second link is the Oracle tutorial:
http://download.oracle.com/javase/tutorial/networking/sockets/... Generally if you can find an Oracle tutorial for
Java then that's the one
you should read.
I should mention that this technique of searching the web works very well when you're looking for Java tutorials about anything at all. I highly recommend it.