Linux comes in many flavors is one typical expression heard for that OS!
Windows likes the first primary by rule on any drive. Linux can easily be put on a separate root and followed with the swap partition(usually 2gb works depending on memory installed). Some favor ubuntu while others go for Mandriva, SUSe, or some other.
One way to see which distro seems to be the best for you is to first try out the live for cd version where you simply see that load from removable media with no changes to the HD made. In fact having one or more live distro onhand can be a big help rescuing files from a drive when the partition somehow becomes inaccessible. I keep Knoppix, Mephis, ubuntu, Gentoo, and Mandriva live distros onhand for this.