O.K budddy,
The main question is "what do you want to use it for" are you going to Dual boot?
For Basic Use I'd Reccomend Ubuntu first up. It is small unclutterd and simple to use. Access to Root terminal. Great for Basic Word processing, and basic office tasks and command line.
The Next step Up is Slackware. This is A bigger distro with more complex layout. Very good for the more in depth linux user. Able to do the basics but you can also re-configure, and do more complex comand line stuff.
I would recomend Ubuntu over slackware simply due to it is eaiser to use... Once you have mastered the Basics then move onto slackware
Try the Live Versions first:
Ubuntu Live:
http://www.ubuntulinux.org/download/
Slackware Live
http://slax.linux-live.org/download.php
Hope this Helps,
Jake