lol, naa, that's what were here for USM.
You won't need to use you black ISA slot in your PC if you go broadband. And (as Upgrader reminded me earlier), depending on what broadband package you go with, you will have a basic broadband modem which will connect to the usb port above. The modem itself is external. There is normally a package you can upgrade to that will provide a wireless router. These routers generally have a Ethernet connection instead of USB, and will use this socket instead:
Having broadband from your phone company, such as BT is normally considered more reliable. Some other ISP you may find cheaper, but bear in mind that ISP's generally use BT, but route your internet connection through them, which means there is more chance of having downtime on your broadband connection.
AOL are the only ISP I would never recomend. It maybe great whilst everything is working, until you do actually encounter a problem, or when you try to upgrade, cancel or remove the software off your PC is when the nightmare begins! You should find the same response from all the staff here, and probably from any tech you'll find around the world.