This will walk you trough the basics of setting up Teamspeak.
Push-to-talk on teamspeak is highly recommended. So use an easy (mouse button?) hot-key. You can find it in the teamspeak settings.
Don't use voice activation as it picks up background noise, breathing and keyboards. This is annoying and can lead to 'embarrassment' when it picks up something it shouldn't.
Go to 'Settings → Options' (or Alt+P). Click on the 'Whisper' section. make sure 'Always show whisper history when receiving a whisper' is off.
Download the custom radio beep (squawk) sound here: whisper_notify.wav. You should copy it to the correct soundpack folder in c:\program files\teamspeak 3 client\sound\???
Read about setting up for channel commander here: whisper_setup