Given the fact that the Instituto dos Vinhos do Douro e do Porto (Port and Douro Wine Institute) or IVDP is the most important single entity involved with the regulation and marketing of the entire Douro region's Port and table wines, this website is the first that I will promote. I have learned about so many facets of the Port industy from this website and actually had the opportunity to spend some time at the IVDP headquarters in Oporto during my last trip. When you have a moment and are sitting back with a glass of fine Vintage or
tawny Port, this should make for a great exploration. You can select Portuguese, English, French or Spanish versions of the site from the IVDP home page:

http://www.ivdp.pt/