Anthony Hawkins' Wine Reference Material
   Searchable glossary provides information about hundreds of types of grapes. Also contains vintage charts and tasting note terminology.
   http://www.stratsplace.com/hawkins/

De Long's Wine Grape Varietal Table
   Offers information about 144 varieties organized in an interactive table. Also sells a print version of the table.
   http://www.delongwine.com/

Enjoying Viognier
   Features news and information about Viognier, a wine of the month, and a searchable database of retailers and prices.
   http://www.enjoyingviognier.com/

Grape Varieties
   Information includes wine styles, characteristic flavors, and vinification methods.
   http://grape-varieties.com/

GrapeSeek
   Searchable collection of links, including grape variety and viticulture resources.
   http://www.grapeseek.com/

P.S. I Love You
   Industry organization dedicated to promoting the Petite Sirah grape. Includes a history of Petite Sirah, articles, a list of members, and recipes of suggested food pairings.
   http://www.psiloveyou.org/

Pinotage Association
   Association promoting South Africa's Pinotage. Contains a history of the grape, winemaking information, and a producer list.
   http://www.pinotage.co.za/

Pinotage Club
   Cyber club for fans of the Pinotage grape of South Africa. Includes information about the grape, a newsletter, links, and membership details.
   http://www.geocities.com/NapaValley/8383/

The Zin Zealot
   Focuses on Sonoma County Zinfandel. Includes links to information about the grape, tasting notes, and a list of wineries.
   http://home.earthlink.net/~nagyv/

Vitis International Variety Catalogue
   Searchable database with very technical information and some pictures.
   http://www.genres.de/idb/vitis/

Wine and Juice Grape Varieties
   Information about varieties suited for cool climates.
   http://www.nysaes.cornell.edu/hort/faculty/reisch/bulletin/wine/

ZOW - Zinfandel on the Web
   Contains tasting notes and links to Zinfandel-producing wineries.
   http://dvorak.org/zinfandel/

Zinfandel Advocates and Producers
   Non-profit organization dedicated to promoting Zinfandel. Contains information about the grape, membership details, and a list of events.
   http://www.zinfandel.org/