Below are some useful travel resources:

Airline sites:
Booking Buddy (Airfare search engine)
Kayak (Airfare meta-search engine)
Orbitz (Airfare search engine)

Information sites:
The Travel Insider (General travel advice)
Gemut (Travel advice for Germany, Austria, Switzerland)
Tours-Italy (Italy)

Government information (passports, visas, recommended innoculations):
Centers for Disease Control (CDC)
US Department of State, Dept of Consular Affairs
Passport Information
International Travel Information

Shopping sites:
Travel Essentials (gear, clothing)
Longitude Books (books)

Online Maps:
Google Maps

Currency Exchange:
XE Universal Currency Converter (perform foreign exchange rate calculations on using up-to-the-minute currency rates)

What Time Is It In ______?:
Time and Date (times for cities all over the world, plus calendars)

Weather Everywhere:
Weather Underground (current and forecasted weather)

Hiking in British Columbia:
Outside Insights (based in Revelstoke)

The trip to Venice and Croatia spoiled me forever. In September and early October I went to China. China is fascinating and we saw a great deal, but it wasn't fun as was your trip. [Competitor company] put it together with 37 people, they nickel and dimed us with tips and "opportunities to show your appreciation" and herding in general. I now know better...
MJJ, Farmington, CT