University of Hawaii System

A great start for those just getting into college planning. Run by the College Board, administrators of the SAT. 

The Common App

An application used by over 700 colleges world-wide. Includes a college database, and virtual counseling. 

College Navigator

Run by the National Center for Education Statistics, this is an excellent tool to find data on any school you want. 

College InSight

This college search database is especially good at giving you side by side comparisons between schools. 

Niche

Student reviews sets this college search site apart from the pack.