From clovegarden.com comes an encyclopedia of sausages and salamis, with good explanations of the differences between the two, how each is made, pictures showing what they look like, and more. It's a fascinating read, even if you don't care for sausage. You can find the encyclopedia here.
Many thanks to my friend John Desmond, who provided me with the URL for this one. By the way, clovegarden has other kinds of information about food that I intend to check out; you may wish to do likewise.