http://www.coinworld.com
2. Coin Facts
http://www.coinfacts.com
3. The United States Mint
http://www.usmint.gov
4. National Numismatic Collection
http://www.si.edu
5. The Coin Site
http://www.coinsite.com
6. US Treasury Department
http://www.ustreas.gov
7. Coin Club
http://www.coinclub.com
8. American Numismatic Society
http://www.amnumsoc2.org
9. NumisMedia
http://www.numismedia.com
10. Rare Coin Museum
http://www.rarecoins.org