The French astronomer Charles Messier was born in 1730. He became interested in astronomy during his early teens, and went on to become a professional astronomer. Between 1758 and 1782 he compiled a list of diffuse objects that were difficult to distinguish from comets through the telescopes of the day.
Discovering comets was the way to make a name for yourself in astronomy in the 18th century -- Messier's aim was to catalog the objects that were often mistaken for comets. Fortunately for us, the Messier Catalog became well known for a much better reason. It is a comprehensive list of some of the brightest and most beautiful objects in the night sky. The catalog, as it exists today, contains objects discovered by Charles Messier and Pierre Méchain.
One of the best resources available today for observing the Messier catalog is David Paul Green's 'The Ultimate Messier Observer's Log' (TUMOL). This excellent publication (in PDF format) contains everything you need to locate, view and log Messier observations with a binocular or telescope.
You can track your viewing notes, sort on several different fields, and print field notes for star parties and Messier marathons. Mr. Green graciously makes this resource available to amateur astronomers as what he terms 'giveware'. Thanks David!