mobile internet

I would like to know what I have to do to get access onto the internet through my iPAQ h5550 using a bluetooth connection on my desktop. I am changing service providers at the end of the week( to broadband.......finally!!!!!!). Will this make things easier? On my device it displays the need to give the ISPs' number for a connection. Tesconet, who I am currently with( you are the weakest link.........goodbye!) would never give this number. Can someone explain in, laymans terms, exactly what I need to do?