The Best way to try Linux is to get a Live Demonstration CD/DVD. These are available in a wide number of distros. The nice thing about these is the fact that you just put the CD in your drive and Boot up your computer. Most computers will Boot directly from the CD/DVD Rom so you just sit and answer any questions that come up on the screen. This type of Linux uses a small portion of your RAM memory and does NOT affect the system that you normally boot into (ex. Win XP, Win7 etc.). So they are completely safe to try without committing to a full-blown Linux Installation.
Knoppix Linux was the first Live linux demo. Now there are many more:
Ubuntu, Mint, Mageia, openSuSE. These are FULL Linux formats, so you can see the most common parts of Linux,
There are also some VERY SMALL Linux Live demos. These include Puppy Linux, Damn Small Linux, , etc. These are particularly good for 'older' computers or for rescue purposes.
There are even Linuxes which will fit on a Jump drive (Puppy, Knoppix, Parted Magic).