[CentOS] IPSec VPN Setup?

Hello Everyone,

I have been tasked at work with setting up a VPN connection from our server to a client's network. The only problem is that I have never done anything like this before, so I am not sure where to start.

We are running CentOS 5.4 on our server. I do not yet know what the client is running for their VPN, the only thing I know of from the client, is we need to use IPSec for our VPN connection to them. I have been googling, and have found quite a bit of information, but it is a little overwhelming, as I am new to setting up a VPN. Is the a "standard" method for doing this sort of setup that I am missing so far?

If anyone has any quick pointers to get me started, that would be greatly appreciated.