We've got cable, and a wireless router that serves our neighbor :~)
I'll ping the ones that know more than me about setting it up.
BTW... you won't regret cable. It's blazing fast :~)
Why do you need a wireless network if you're going through cable? If you have your house for cable, you can hook up a computer in each room that has a connection. True you may be out a modem but build slowly. Wireless is pretty much straight forward. To set up a wireless network without the neighbors tapping in you are going to have to read the directions.
If you have 2.8 GhZ cordless phones, this can cause problems. They operate on the same frequency as do wireless networks. If the phone rings and you answer it, your network goes down.
If you have a computer set up already that you want to have broadband access, Comcast should run a split to that area. If you want to access via wirreless, the router must be able to do it. Otherwise, you might need something like a Wireless Access Point to plug into their router.
Without all the details about what you have... it's hard to be more specific.
Good Luck
If your router is linksys as mine is, I think you'll find a file called NetAssistant on their site much more helpful than the enclosed software. At least I did.
Now, the single most important thing you can do is to not forget the dammed antennae.
I spent three hours trying to figure out why I couldn't get the signal strength I thought I should have.
Went to the box the wireless card came in and, DOH!