My problem is that once the VPN is established and I am on the network, none of the shares or resources are visible or able to be connected to.
VPN gets you connected to the network as if you were physically present in the office, but nothing more. Once you have successfully connected via VPN, you have to perform a seperate step to actually login to the server.
Also, some of the "it just works" aspects, like seeing all the things you can login to, before actually logging in to them, is a feature of Bonjour, which doesn't pass over VPN. You'll probably have to use the Finder Menu GO -> Connect to Server, and then type the server's IP address in manually.