I want to write a windows service program which will run at windows startup as service. This will check a mySQL table and do some updation work when a condition satisfied. How to implement it? Pl help for some books where to find this types of programming help.

There's really no special coding necessary... write the Java code as you normally would, if you have multiple classes you will want to jar them up. If you need to reference outside jar files you might want to use One-JAR. (Deliver Your Java Application in One-JAR™ ! (http://one-jar.sourceforge.net/))

Microsoft has a utility that will allow you to run your application as a service. Here's a link that will help you with that: Create your own user-defined services Windows NT/2000/XP/2003 (Windows NT/2000/XP/2003) - TACKtech Corp. (http://www.tacktech.com/display.cfm?ttid=197)

Good luck.