The easiest way is to add the IP (gccsgo1.game.nfoservers.com:27015) to favorites. To do that you click "Play" from the main menu, click "Browse Community Servers", Favorites Tab, Add Server button on the bottom right, and paste the IP in. From there you can join the same way by double clicking the server in the favorites list.
Alternately, you can open console and type "connect gccsgo1.game.nfoservers.com:27015"