HT-488 Help Needed

I’m feeling a bit stupid, so please help me out here.

I’ve got Asterisk 1.4 installed, have got extensions configured, and can call back and forth.

Now … the HT-488. I can’t figure out how to configure Asterisk to use the HT-488 so that I can make outgoing calls through my PSTN or answer incoming calls.

Can somebody please post some notes on how to do this?