What should I use for online security with Comcast Cable Internet?

I think switching the dial to Comcast Cable Internet? Does my Norton Internet Security and Spysweeper be sufficient for safe online? Some people have suggested that I get something called a router. What do I really need? Thanks Thanks

omg i had dial up for most of my years and was pain! the money you spend on broadband is soooooo worth it! I have a router its just to be able to use the Internet on other computers to and no cord is necessary. Norton slows down computers that Ive heard from my model slowed, get McAffee

F-Secure evolution of security