I want to create a VPN to my SBS2003 server from the internet. I have a PIX 501 but I don't have any clue where to even start in setting up a VPN. Can somebody clue me in? (I can't even find any documentation for the PIX 501)

I just installed Small Business Server 2003 and am using it for Email (exchange) services. OWA works great inside the network but it is so slow outside the network that I know something is wrong. How can I identify if it is something in the PIX 501...