Well... Since your not really familiar with any Distro, then I would start with a Distro that has an easy learning curve, and that is somewhat Industry standard.
I would recommend Red Hat, unfortunaly will soon leave the GNU scene. My other choice (equal) would be Mandrake Linux. Mandrake has a learning curve that is easy on the brain, and they won't be leaving GNU anytime soon. Mandrake is Red Hat compiled on x686 vs x386 (Red Hat), so on newer machines Mandrake technically will out-perform Red Hat. Other than that they are about identical, including the URPMI RPM manager. Mandrake has a bit more newbie administration tools than Red Hat. I have four servers running on Mandrake. Read up on MSEC it's a wonderful tool for security, makes iptables (firewall) easy.
Then once you get back in the flow of things you can with confidance go to another Distro.
Remember, the important thing is to get back into linux, even if you have to use training wheels for awhile...
Mandrake can be stripped down to your specs.
Hope this helps...