Install Starfleet Command: Empires at War on a pre-Vista windows system. Patch it to 2036. Run the directory server update. If you have a router know it very well and understand what a static lan configuration is and how to forward port ranges. Allow pings from the WAN.
Edit the EAW shortcut to skip the video (point it at Starfleet2.exe). Run it. Wait for the menu, slelect multiplayer then select Dynaverse. Wait a m inute for the login button to light up. Enter your gamespy login information. If you do not have a gamespy account, go get a free one. (They will try and suck you into paying, they hide their free service). You will get a serverlist... give ti another minute to update... select the server you want to play on, and click login. You will be prompted to select a race and character name first time you login to a server. If you ant another character, use another email.
I think that basically covers it.