In my opinion, the best guide books for budget travel are the Lonely Planet guides. They pretty much span the globe.  For more information on your favorite destinations with Lonely Planet guides click below.

Setting up domestic travel alerts on Travelocity is one of the  most effective tools to learn the rhythm of airline sales, when to travel and what airlines are most likely to have the fare you need.  These alerts are called Fare Watcher^tm  by Travelocity and can be found on its Home Page in the center.

Here's how Fare Watcher works.  You will first need to give some information to Travelocity and get a pin number.  You will then have access to this program. Travelocity allows you to choose five destinations you are considering visiting.  You will then be invited to tell them to send you an email each time the fare goes up or down by a minimum of $25.

Each time there is a variation of at least $25 you receive an email inviting you to look at the available fares. There are two major benefits to this program: 1) You save a ton of time checking fares every day for destinations you care about. You are able to watch and choose when the fare is in your interest. 2) You start to learn when and how often the airlines have their sales, and, of course, what the average lowest fares are for your favorite destinations.

For international fares use kayak.  You are allowed only one destination.