The web makes looking for colleges and universities easier than it used to be -- most institutions (and astronomy and physics departments) have comprehensive web pages. In addition there are websites that have already gathered a lot of this information. Two sources of information on colleges, with links to sites that list scholarships, grants, and other financial aid, are U.S. College Search and MatchCollege, which list thousands of U.S. colleges and universities including school contact information, website addresses, enrollment information, and student demographics as well as career guidance and financial aid information.
For Graduate School information try GradSchoolShopper , which lets you search for graduate schools in the physics and related fields, e.g. astronomy, by degree (masters or doctorate), location. It also provides links to career advice and resources.