Drop both conf files into /etc/openvpn and /etc/init.d/openvpn should pick up on both and fire them up. Configure the ip addr of your host you wish to vpn through in the configs on the server lines.
Key difference is the openvpn-split.conf only pushes routes for netblocks you want to route over the vpn. In the below case, its the two routable /16s. The openvpn-everything.conf pushes a gateway down to clients, shunting all traffic through the vpn endpoint. Also push DNS servers if you have records locked up in campus DNS.
You also have to do all the easy-rsa business which is fairly well documented on the web. Drag the client certs which come from that business over to your vpn client. I use Tunnelblick in OS X.
Tested using openvpn-2.2.2-1.el5.rf from rpmforge on CentOS 5.8 in a Xen DomU.