FOR THE LARGEST AND CHEAPEST DATABASE OF FLIGHTS, HOTELS, CRUISES ETC VISIT:
Kayak.com This site puts all competing sites against each other to find the cheapest possibility online. Even suggests calling certain companies if that is the best choice.
FOR TONS OF COMPLETE INFORMATION ABOUT A PARTICULAR DESTINATION VISIT:
Lonelyplanet.com Includes When to go, pre-made itineraries, Events, Sights, Currency and Costs, Transportation, History and LOTS MORE!