Installing tarballs--please help

[spankler]

I am new to linux in general and have an older sysytem that I successfully partitioned to run ubuntu, kubuntu, and *******. I was a casual mac user before thius and am used to packages--so I have no exp. installing tarballs. I am trying to install xampp and successfully downloaded it, but now am at a loss as to what to do--nothing seems to be working. I am using firefox which for some reason is not saving to downloads even though that is what I have set in pref. Is there a way I can use apt-get for this (although my understanding of that isn't much better. I can't seem to find the relevant information in documentation. Would someone please help me w/ some step-by-step inst. or equally remedial docs?
Thanks to any and all who help out!

[sikander3786]

Is it only tar packages that are not showing up in the Downloads folder or anything else downloaded through Firefox also doesn't show up anywhere?

There are many tutorias on installation from source.

http://www.ubuntugeek.com/how-to-install-source-files-in-ubuntu.html

You can extract the source package and will contain a text file named with Readme or Install and that contains all the instructions for installing that package.

And Checkinstall is even better. In my opinion the best way of installing tar packages.

https://help.ubuntu.com/community/CheckInstall