Java Network Programming, Second Edition
Elliotte Rusty Harold
O'Reilly & Associates, 2000
ISBN: 1-565-92870-9
Java I/O
O'Reilly & Associates, 1999
ISBN 1-56592-485-1
Web Client Programming online course
This presentation: http://www.ibiblio.org/javafaq/slides/sd2000east/urls/