In the King's Gambit, white offers up a pawn on move 2. If black accepts the pawn, and most players do, white gets active development and control of the center as compensation. Enjoy these games. There are vigorous attacks and wonderful combinations. White does not always win, as you will see, but the games are almost always interesting!
Related literature
The King's Gambit As White, Robert Raingruber, Lou Maser, Bob Raingruber.
The King's Gambit: A Modern View of a Swashbuckling Opening, Neil McDonald.
King's Gambit, George C. Chesbro.
Who's Afraid of the King's Gambit?, Eric Schiller.
Video on the King's Gambit
The King's Gambit. IM Andrew Martin reviews the ultra-dangerous 1.e4 e5 2.f4 exf4 3.Bc4! GM Morozevich has brought this system back into the limelight and used it to crush World Championship Challenger Vishy Anand. The video also covers the King's Gambit Declined.