Home to Office network

I'm running a small travel company with 3 computers in the office, and one person working a 4th computer from home.

Currently the 3 office computers are linked in a simple network, and each person can share files with another (one computer hard drive stores most of the important shared files).

I want the 4th person to be able to login and share and update those same files as easily and securely as possible.

We are running XP Pro on all machines - currently Norton anti-virus, and a mix of Zone Alarm and Wondws XP firewalls.

Thanks

 

Do you need the person at home connected all the time or just when files or other information is needed?

Does the person at home connect to the outside world via dial-up modem or broadband of some sort?

 

Home person has broadband permanent connection. They just need to get to the server whenever they need to share/update files.

 

General VPN information
http://compnetworking.about.com/library/weekly/aa010701a.htm

You do (and if you have a fixed IP address, it works fine with broadband at your end and this is the best how-to I could find)
http://www.wown.com/j_helmig/xpvpnsrv.htm

"Home person" does
http://compnetworking.about.com/od/vpn/ht/newvpnwindowsxp.htm