Acessing home network through internet

Ok i have two xp machines on a network. One wireless laptop (Home edition) and one desktop (Pro). I run this network off of a D-Link 614+ (Ver B). Everything seems to be running great, but I was woundering how I can access this through the internet. I want to be able to be at school somewhere and access my home computer. Does this require a VPN? My router supports VPNs and will act as a virtual server but does that require software for that laptop? I really don't want to go out and buy more software. Can I just set up a private port with a user name and password? And if I can, how? Do I have to do this through my Windows xp or through my router? Any info will help, thanks.