Arguably one of the best resources for Servlet Programming around. Four of five stars from readers at Amazon. Developing Java Servlets by James Goodwill, Sams, July 1999. New edition scheduled for May 2001. Assumes some Java background.
Book is a good reference.
Java Server Pages by James Goodwill, Sams, June 2000. Java Developers Guide to Servlets and JSP by Bill Brogden and William B. Brogden, Sybex, October 2000. Core JSP by Damon Hougland and Aaron Tavistock, Prentice-Hall, December 2000. Wrox Press Inc . This is a BIG book that gives an overview of many different technologies.