Searching with Google can be a magical experience—in seconds, you tap vast storehouses of information on servers in almost every part of the world. In mid-2008, Google announced that its computers had indexed one trillion Web files, so you’re likely to find things whose existence you never even suspected.

That’s also the challenge. If you want this amazing resource to find the knowledge you need—and quickly—you must make your queries efficient by learning some advanced searching techniques, whether you want a quick overview of a topic, a fact to help you make a point, early evidence for an out-of-the box hypothesis, or the time when your flight will depart. Many guides to using the Google search engine are available on the Web; what I hope to contribute here is a more user-friendly approach to doing Google searches, as well as offering some suggestions on how to get the best from Google when you are on the road.

What Google can—and can’t—do

While Google’s reach is vast, its computers can find only what is publicly available on the Internet (for tips about finding information on the “invisible Web,” see sidebar, “Google mysteries”). That excludes a universe of information its owners don’t...