Are you not seeing as in cannot ping, or not seeing as in cannot see when browsing?
If you cannot ping using IP addresses, you may need to add a route in your default router pointing to the vpn server for the network range that the vpn server is handing out. (If RIP is turned on, you do not need this.)
If you can ping using IP addresses, but not by name, you are either not reaching a DNS server or the server you are using does not know about your internal machines.
If your problem is that you do not see machines when browsing, you need to install Client for Microsoft Networks and the netbeui protocol, if not already installed. In your LMHOSTS file, add an entry, with #PRE and #DOM tags, which provides the IP address of a browse master on your main network. This would typically be a BDC or PDC. This allows your remote computer to immediately locate a machine on your network that can provide the browse list.
Good luck.