Hi Naresh, Welcome to coderanch..
First get knowledge on core java. If you already have knowledge on java, you can go ahead learning servlets and jsp. Lot of tutorials are available in the web, search it. In the books, you can go with Head First servlets and JSP, which is a very good book for the beginner. If you have any questions or doubts, you can always come back here and post, we will try our level best to help you..
on a side note, nothing is easy to learn, you have to make yourself easy, for you, by studying and doing lot of practice..
First start to learn servlet first. read all basics about request and response concept in servelt. Then learn about Servelt Reqeust and Servlet response. You should also learn one more basic concept servlet life cycle. It will give you complete idea about servlet.
Always learn with practical example program. do that program in system. from the starting host your servlet page manually to the tomcat server. once your page is running properly go with any IDE.
In the middle of the servelt tutorial you will can start to learn JSP concept. that is the best thing to lean servlet and JSP.
Download and install the latest Tomcat implementation of the Servlet and JSP API so you can have real servlets to experiment with as you are reading about the concepts. The usual download includes lots of examples for both servlet and jsp.
Install Tomcat as an application, NOT as a service, so it will be easy to stop and restart.