Couple of things to add that I did not see posted.
Modem you picked is good, one of the best, and it meets the standards the cable companies want when you use your own.
1. The modem will probably have both a USB and a Ethernet jack. Use the Ethernet to connect to the computer, it's much more fool-proof. I have dealt with quite a few issues with Windows and USB connected modems, and have not seen one yet with Ethernet. You should pick up a few 6-10ft cables, you need 1 for modem to router (see #2) and one for router to PC. One issue with bying your own, if you have issues with the service from the company, they will try to blame the modem, which means you are stuck with maybe having to buy a new one to appease them before they will trouble-shoot further. This is not a given, but I know when it comes time to fixing things, pass-the-buck is a game that is played by techs, especially 1st level support that read from a script.
2. Before connecting online, buy a router (about $30 for no wireless, $50 for a wireless one). Even the cheapos will have a servicable firewall and will keep your PC hidden from most basic online attacks. Read the router manual to help you set it up, it's fairly easy but if you are new to the computer network thing you can hit a snag or 2. Do a search on Newegg for a router (make sure it has 4 ethernet ports so you can connect another PC if you want to later on). Just about any brand will work fine, Netgear, Linksys, D-Link are 3 of the most common ones.
3. The cable company will probably ask you for the MAC address of the router, so note that. It should be on a label somewhere on your modem.
4. Get an anti-virus software AND anti-spyware. 2 I use that are free is AVG anti-virus and Spybot Search and Destroy. Once you are on broadband and are downloading all sorts of things, you will really want those if you don't have them set up already. The seedier parts of the NET are filled with nasty things that will want to chew up your computer and spit in your coffee. Beware music/warez/movie download sites (not the pay ones I'm talking about the pirated stuff), you can very easily ruin your Windows setup with what some of those sites try to do.
5. PM me for all the good porn sites once you are online

))
Good Luck with your setup.