"A loosely organized reform movement originating during the English Reformation of the sixteenth century. The name came from efforts to 'purify' the Church of England by those who felt that the Reformation had not yet been completed. Eventually the Puritans went on to attempt purification of the self and of society as well."
(Mark Noll, "Puritanism", Evangelical Dictionary of Theology, 1984)
Here's a brief but impressive video on Luther -- hosted by that friendly European tour guide and Lutheran, Rick Steves! Runs about 30 minutes. Hooray for Google video!
"All those nick-names of Puritan, Precisian, Hypocrite, &c. with which lewd tongues are wont to load the saints of God, are so many honourable badges of their worthy deportment in the holy path, and resolute standing on the Lord's side."
Robert Bolton (1572-1631)
Get to know several puritan classics by reading one book