DSL or Cable
This question has been ongoing for quite some time.. Theoretically, cable is supposed to be faster.. BUT, and this is a big but, the number of people using cable (tv and broadband) in your area has alot to do with your speed.
If you were the only person on that cable leg, then your speed would be fantastic.. However, as you turned on your tv, another computer, other people turned on their tv's and computers, you would quickly notice a reduction in your speed. Reason: They are using the bandwidth and the more that turn or logon, the slower you will get. NEVER as slow as dialup though.
As for DSL, you can sign up for a multitude of download and upload speed options.. Mine is 1500 down and 128 up. This will NEVER change.. My actual download and upload speeds aren't quite that (1415 down and 109 up) but they remain consistent no matter how many people are using the phone or are logging onto the net.. including my own network. My phoneline is mine alone and no one else can take any bandwidth from it...
As far as networking is concerned, www.practicallynetworked.com
is about the best tutorial site I have found for this.