Preferred network issues and xbox live issues with my new airport

Hello everyone, wondering if some brilliant mac-minds could help me out of my two intertwinded dilemas. Please note that although I own a mac, I am in no means and advaced user.
First off I have a Mac Book Pro with a new Airport Extreme. The internet connection is very good when it wants to be. My only real problem is when I start up or sleep. My network is saved as preferred in my network utility (i think), but it still makes me manually connect to my network. Has this happened to anyone before? What is the best/easiest way to fix this?
My next problem is with my Xbox 360 live. I played it today successfully for about an hour, then it crapped out saying 'information could not be retrieved from the server'. I have looked around for this fix but the only thing I could find i couldnt really understand.
Anyway, hopefully some people out there can help me out with one or both of these problems? Please also remember that a dumbing down would not be out of order, as I am not a crazy advanced user like most of you.

Thanks for you help.