This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
Yes Bear is right, if you are not using annotation base servlet then you have to mention your servlet along with the mapping in the web.xml file
If you will use eclipse like any ide for creating your servlet that part done automatically by the IDE.