The ADF is using TeamSpeak 3 for internal comunications, here are the instructions on how to use it.
 

 
First go on the TeamSpeak website in the "Downloads" section.
Then Click the "Download" button next to "Client 32-Bit 3.0.0-betax"x is the beta version.
Beta versions download all the time, so please keep an eye on that site.
Download the version for your operating system. In the example above i showed 32 bit to download.
If you have 64 bit operating system, then download the 64 bit version
Finaly Click "I agree" link on the very bottom of the end user agreement (EULA).

http://teamspeak.com/?page=downloads

Once its downloaded, install it.
(No special settings are needed during the installation.)
 

 
Start Teamspeak and click on "Connect" in the "Connection" Menu.
enter the following information in the fields:

Server Address:	startrekfleet.com
Port	9987
Nickname:	[The "In Game Name" you provided in the Membership Application Form.]
Password:	[None at the moment.]