This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
JRun is a fully compliant J2EE application server while Tomcat is just a JSP/Servlet container. It's obvious which one is better but maybe Tomcat will better suit your needs(i.e. practice with JSPs and Servlets).