Voice Work--how do you get into it?

I’ve been told by lots of folks that I’ve got a “voice for radio.” (Jury still out on the face.) Most of these folks tell me that I ought to do voice work–commercials, voice overs, radio, etc. While I’ve got no special desire to do this as a full time career, I admit that it might be nice as a side job.

The trouble is that I’ve got no idea how to start with such a thing. Obviously I’d want to start with some sort of a recording, but what should it it include, and to whom should I send it? If any of you fine folk have any ideas, I’d love to know!