For Passports, Visas, Travel Warnings, and Consular Reports:
• U.S. State Department

For information about vaccinations, diseases, and Illness or injury abroad:
• Centers for Disease Control

For Air Travel: 
• Delta
• United Airlines 
• American Airlines 
• Continental

For travel planning:
• travelocity.com
• orbitz.com
• cheaptickets.com

Information about language instruction: 
• Berlitz
• BBC Languages

Information about world cultures:
• BBC World Religions 
• National Geographic