IAMPETH (the International Association of Master Penmen, Engrossers and Teachers of Handwriting), which describes itself as "an international, non-profit association dedicated to practicing and preserving the beautiful arts of calligraphy, engrossing and fine penmanship," has an absolutely wonderful, treasure-trove of a website at www.iampeth.com.
Highlights of the IAMPETH's website include the gallery of Master Penmen from the Golden Age of Ornamental Penmanship (replete with biographies and work samples), but by far the greatest thing this site has to offer is a PDF library of dozens of scanned, downloadable rare books filled with beautiful calligraphic designs.