Tactical Gamer has its own TeamSpeak server. http://www.tacticalgamer.com The front page has a news announcement about the new TS server address. Be sure to regularly check the front page since things change all the time.
I assume you know how to connect to a TeamSpeak server once you have the IP. If you don't, take a look at TeamSpeak's manual. No password is currently required for TG's server and registration to the server is not necessary. Once you're connected to a TeamSpeak server, start JO and play.
I'm not sure if you've posted here to inquire about playing on the Tactical Gamer JO server. If you are looking to join the TG server, keep your eyes on this thread so you know when it's running smoothly.