Douro wine region, Douro river trip tour, Port wine wineries visiting.

First of all, excuse me for misspelling previously the Port wine word.

I am planning a trip to the Douro region.

Can you all please tell me anythign related to tourism in that area
and Port wines too.

I want to travel by boat the Douro river, from what city to what city
is the longest distance I can travel by boat? YOu know any boat
companies or websites you have used before I can refer too ?

What are the best Port wine wineries to visit?

What is the best Port wine guide book ?

What is a very good book on the entire Port wine region ?

What are the cities I should stop by and visit during the Douro trip
travelling ?

Thanks,

Mario