The FCC (Federal Communications Commission) has created a very good information section on Broadband Services for the Home.

The FCC Broadband Comsumer Guide can be found on the web here.

The FCC site has a section that could help you decide "What Speed Do You Need?" It explains what internet speed is needed for different internet activities, email, web surfing, video streaming, etc.)

The FCC also lists a "Household Broadband Guide"which considers what speed you might need if you have more than 1 computer or device using the internet at the same time. Do you plan to have multiple users using multiple devices (PC's, iPad, BluRay Player, Roku, Video Game Device (XBox, etc.)). If you do, you might need a faster connection than if you are using a single computer.