The installation of tomcat  is very simple. unzip the
files into a directory. Set a system level variable
named as "JAVA_HOME"

If you specifically tell me the OS I will be able to
tell you what are the commands.

The JAVA_HOME should point to the directory where the
JDK is intsalled.

the command in windows is usually

PATH=%PATH%;c:\jdk1.3.1;

In unix dervived machines it is

PATH=$PATH:/usr/local/java/jdk1.3.1:
export PATH

The open a command prompt or terminal window in
%TOMCAT_HOME%\bin and execute the startup.bat file.
This will open up another command prompt and start the
tomcat JSP servlet engine. By default the port will be
8080

Navigate to the URL page http://localhost:8080/ to
view the startup pages of the tomcat webserver.

IF you need any other configuration changes please
mail me and I will inform you about the corresponding
XML files that need to be changes.