Conrad,

Short lesson in English history:

Guy Fawkes was one of a group of conspirators who plotted to blow up the Houses of Parliament when the King (James I) was formally opening parliament, thus killing the king and much of the English aristocracy. The plot was a failure as the conspirators were pretty incompetent and the authorities came to hear of the plot and caught Guy Fawkes with a large quantity of gunpowder in the crypt of the Houses of Parliament on Nov 5th, 1605.

The bonfire and fireworks were originally in celebration of the foiling of the plot and it later became customary to burn an effigy, called "The Guy" on the bonfire though the original effigy was of the pope as the plot was aimed at killing the protestant king and replacing him with a catholic.

Don Firth has correctly listed up the things we eat on Guy Fawkes night.

You can get more info on the gunpowder plot, as it is known in Wikipedia which provides a pretty good summary of the main events.