Most modern installs of Linux now offer dual boot options as part of the 
start up.  I've done this with Suse linux now 4 times on 2 different 
computers, without any problems.  They detect your current OS, and let 
you repartition your drive, or select another drive to use for the 
linux.   Be sure to remember to allow the installer to set up a swap 
partition for Linux, as well.  This is a small partition used pretty 
much like the MS swapfile, but for linux.

I've never had a problem with this, but you ARE messing with your main 
OS, so be sure to do a good backup, first!  Don't do it unless you have 
a full backup, and/or are willing to re-install windows if something 
goes disastrously wrong.

A better choice for you, since  you just want to play with Linux, is to 
use a LiveCD. See my NEXT message - "Learn Linux with a LiveCD."  :-)

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