To connect to scoutlink teamspeak you first need to install the client. We recommend using the computer client as it is free, though there is a teamspeak mobile app that costs about £1 if you really want to use your phone.
To install teamspeak on the computer go to teamspeak.com/downloads and download the client appropriate for you. Most people will want windows 64 bit.
Once downloaded just run the application that was downloaded to install it.
The first thing you need to do, is join a channel.
To do this, just find one in the list on the left hand side that you want to join, and double click it.
Once in the channel, just press and hold the hotkey you assigned earlier to talk, and release to listen.
Simple as that!