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/

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/

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/

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/

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

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

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/

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/

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/