Need help setting up VPN

I am trying to set up a VPN between home and my main office computer. I am doing this in anticipation of a software upgrade that changes from single to multiple workstations.
I have done some studying but on some areas probably don't know how to ask the right question.
The home computer is running Windows 7 Pro 64 while the office is Win 7 ultimate 64 - everything up to date. Running Comodo Firewall and Symantec Endpoint Protection on both ends. Using Netgear wireless routers on both ends - 3700 at home and 4000 at office - although the computers are wired connections.
My service at home is Charter cable; office is DSL Bellsouth I think (Provided me - have no control).
When I run ipconfig both are listed as 192.168.1.X - prob assigned by the router.
I have set up port forwarding on the office router. Do I need to do this at home also?
I have set up the VPN connections on both ends but cannot connect - error 800.
I have a feeling there is more to this like what IP address do I need to be using?
I am also not sure what there may be upstream of my office computer in terms of switches, routers, etc.
I would appreciate any help anyone is willing to provide.
Thanks!

You need to talk to the company IT staff about this. Among other things to be sure that what you are attempting is permitted by company policy. Allowing access via VPN raises a variety of security issues.

This is my personal office so it's a moot point.
I just don't control the incoming service per se.