I am thinking about setting up an Asterisk server, and am kinda confused at to what I need. Does anyone here have a PBX server? How exactly does this work? Where do I get a phone number from? Can I buy a phone number from some company like I buy my domains from GoDaddy? Do I need a VOIP service provider? If so, why if I am hosting the number locally on my PBX server? What products do I need, any good tutorials/books you would recommend?