jfruch1 gave a great link
How To Install Software in Linux appliies to all distros
Slackware Linux Essentials is a good primer
I got a barebones Shuttle KPC and a bunch of good used hard drives and simply installed different distros on different drives, swapping them out as I saw fit.
Nowadays, Virtual Machine does the same thing albeit a little more dearly for the hardware that will handle whichever flavor of VM decided upon.
Don't be afraid to have to reinstall, either.
SystemRescueCD is a great tool. I suggest learning it and the CLI, too.
Just go fo it!
Edited by pane-free, 21 February 2013 - 10:04 PM.
There comes a time in the affairs of man when he must take the bull by the tail and face the situation.
W. C. Fields