John,
A way to dip your feet in for Linux is to use your Windows 7 machine to run a free virtual machine client called
Virtualbox.
You run Virtual box as an application within windows. It allows you to run "virtualized" installations of an OS... it could be Windows, a Linux installation, or whatever. Free pre-built virtual installations are available for download (see the first bullet at the link I gave for Virtualbox). Or, with just a little experimenting, you can install a fresh copy of whatever Linux distribution (or "distro" for the cool geeks in the room) you like. I recommend strongly Linux Mint Cinnamon. I have a Vbox of version 17.3 of that. It's relatively easy to use, though you will need to learn how to do some things in Linux that Windows takes care of for you.
Have fun!