Sources for Maps

United States

Map Maker from NationalAtlas.gov:  a great tool for creating the exact map you need.  Boundaries, ecology, geographical features, population...many options.

Outline & Blank Maps

Clasroom Clipart Maps

Free Blank Outline Maps from About.com

Owl & Mouse Online Atlas

Perry-Castañeda Library Map Collection

Physical Maps

DK Maps

Map Collections

Public Domain maps at Wikimedia