Mac & Linux

I'm looking for people to help me out with these Operating systeams, i'm just doing a forum to help our member with their pc & internet problems,

Can anybody tell me steps how to disk cleanup, Defragment your hard disk drive and any other ways of keeping your pc in shape on this OS.

Afaik in Linux you don't need to defrag,you can but its not needed as much as windows os.
I use ubuntu and will not pretend that I am an expert, but I have used it for 5 or so years. As for Os cleanup there is a programme called janitor in ubuntu that will clean up the junk from your system but again it's not really needed.
Linux seems to handle daily use a lot easier than windows and tends not to leave junk files everywhere.
It is harder to install stuff but this is a plus 'cause it makes it almost impossible to pick up nasties.
You can use a live disk on your machine and it will give you an idea of whether you like it or not and best of all its mostly free software so it's no big deal if you don't like something just uninstall it.

My hubby likes to use Linux as its free and reasonably easy to use. It looks similar to Windows too so easy to navigate around.

Here is an excellent site about cleaning up Ubuntu.....

http://www.ubuntugeek.com/cleaning-up-all-unnecessary-junk-files-in-ubuntu.html

hope this helps.