Nice to read you are back in business
IIRC, installing tomcat is not that difficult.
1) Install the java jdk 1.5.0
You can download an executable binary. If compressed, extract it, and run the installer. I think it asks you where you want to install java - perhaps /usr/local/ would be a good place.
If done, you should have a directory similar to /usr/local/j2sdkblablabla. I would do a symlink "ln -s /usr/local/j2sdkblablabla /usr/local/java" for convenience.
2) Istall tomcat.
Installing tomcat is just downloading and decompressing the file. A good place would be /usr/local/jakarta-tomcat-blablabla. Again, a symlink "ln -s /usr/local/jakartablablabla /usr/local/tomcat" would be nice.
3) Starting tomcat
To start tomcat, you should do at least two things:
# Set the $JAVA_HOME so that tomcat knows, where to find java
# Start tomcat
Write a little script for this tasks.
You can do all these things as non privileged user. Simply create a user, log in as that user and you can do everything without any chance to wreck the system. Off course you cannot manipulate the /usr/local directory, but tomcat runs fine in /home/myuser/tomcat, too.
Java can be in /home/myuser/java. If everything works to your desires, you can copy the files into any system directory later.
CAUTION: I write all this out of my head! This is no howto and no step by step instruction, there surely are some details not mentioned. And the most important: I did not test it. I think, I always do it the mentioned way, and I don't think, that these steps above can harm your system.
And another thing: I don't know how experienced you are - if you want to manage a productive server, please make yourselve comfortable with Linux tools and the servers you want to run. A lot of spam is made possible due to misconfigured servers, e.g.