Go http://www.google.com and in the search box type in the letters VPN and then click on Search.  Most general computer questions can be answered using this procedure.

Steve

If you're using XP Pro, VPN is built in and very easy to setup.
Depending on your ISP and if you have a static or dynamic IP address, it could be a very easy setup. There are other considerations if you're using a network or just a direct internet connection.

Microsoft has excellent application notes but an even better site to check out is www.dslreports.com and go to the VPN Forum. At the very top of the forum messages is a very extensive FAQ for VPN that has the most complete description of VPN that I've seen anywhere.

There are a few other sites I can recomend but dslreports is a good place to start.

GL
Mike