Set up ISP

I am going to start an ISP business and need some help. I have a server i am building (i’ve been building for years so i know what it needs) but i am not sure how to connect the phone lines coming to my building that people use to dial into my service to my computer. Some where i read that i should use us robotics modems but which ones? how do they need to connect? How many/what type of phone lines do i need for this application?

I have a 416kbps DSL line going to install at end of january, or earlier. I plan on doing about 30 or so people for the first few months, i have half that ready to come to my service.

I would appreciate any help you could give me.

Thanks,
Mike Aalderink
maalderink@hotmail.com