The 2.13 patch should be available for download
here (Mac 2.13 patch; I hope I didn't link to the wrong OS).
There are a few servers for TCP/IP games (such as
Mosehansen ), but other games are done via PBEM, especially if you cannot find a spot on one of the public TCP/IP servers.
Using a server is very useful if you want quick games and/or cannot find a reliable host for a PBEM game. Otherwise, I must admit I tend to prefer a PBEM game; but then, I prefer to keep it simple when possible (that, and I can no longer do TCP/IP).