Someone Please Help Me Set Up My Xbox Live?

ok so I have an ethernet cable and I plugged one end into the xbox 360 and one end into my modem. i dont have a router. my modem is a comcast one, it's model type is like 57then a few more numbers after that, i cant remember. I couldn't connect to the network at first, then I connected to that. now no matter what i do it wont connect to the "internet" phase of the xbox live connection. could someone please give me some suggestions. maybe leave your email too…in case I have more questions or it doesn't work? if you can give me suggestions that get it to work i can get you like 100 answer points on this yahoo answers.

Suggestion:

I would try a different Ethernet cord, the one that comes with the 360 can be a little iffy when it comes to straight internet connection.