How to install Tomcat and Java 6 on CentOS 5.2

I’m not very smart on installing packages on Linux, but today I need to configure a Tomcat on a CentOS 5.2. The CentOS 5.2 has Tomcat 5 available as yum package, with gcc-java. But Java gurus tell me to use the original Sun JDK to run Tomcat without problems.