Get an OS at the grocery store magazine rack.
The June issue of Linux Magazine will have the usual DVD but this time it will have Linux Mint, PCLinuxOS, Sabayon, Puppy Linux on it.

For those who haven't tried Linux, these are complete operating systems. Mint is an Irish project, PCLinuxOS is US I believe and Windows-like in appearance if I recall.
Sabayon is Italian in origin and Puppy is Australian.
They are all based on the Linux kernel and use various desktop managers (desktop environments) such as Gnome or KDE.

These OSes can usually be run in "test drive" from your optical drive, so you can play with it without a full download/install.
They will not run at full speed unless they are installed however. Puppy is an exception, especially if you let it create a small Save File.

Puppy is a lightweight that loads primarily in RAM. This makes it very fast and it's great in older computers. If you have a retired Windows box lying around, try Puppy on it.

I have found Puppy to be very capable in getting wireless cards up and running. Support is very good from the Puppy folks and the OS geared toward the non-geek. Puppy is a great first Linux experience.
It's fun to compute without having to kiss Bill's ring.