Hi Renis Welcome to Javaranch. You would be very confortable while sharing your problem in this forum.
If you are a new in Servlet then Go and purchase "HEAD FIRST SERVLET & JSP" By Kathy Sierra,Bert Bates, Bryan Basham.
Now you asked what is the differnce between the servlets and jsp? I will explain you.
Servlet and jsp both are server side programming language. but the difference is that the Jsp contains the server side code as well as html code( which is for the view for the client/user).
jsp is automatically tranform into servlet during the translation time.
whenever the servlet code is changed then the user has to recompile the servlet and redeploy the servlet restart the web application(Tomcat/weblogic/websphere/jboss/jrun etc). But in jsp the programmer doesn't bother about the recompilation, redeployment and restart the web server. all done by the Jsp container.
Today everybody knows that the changes in teh web application is done at the client side rather than the server side. Thats why jsp is suitable.