Setting up a vpn network with a Linux mint server

I’m in the process of trying to set up my own private vpn on an old Pentium 4 small form factor desktop. I loaded Linux mint 16 cinnamon on to it. Using terminal I installed openvpn and network manager. I am somewhat confused on how to configure it. Does anybody have any experience in this sort of thing?

I haven’t messed with OpenVPN, but this seems like a pretty comprehensive guide: https://help.ubuntu.com/community/OpenVPN

Not directly related, but I noticed my router with DD-WRT had a service for setting up an OpenVPN server. Might be easier to use that than setting it from scratch.