I recently came across the excellent site, Liam’s Pictures from Old Books, and while browsing came across scans from Letters & Lettering: A Treatise With 200 Examples.
When I had first decided I wanted to design typefaces I looked around for books on the subject, and yet could never find any book that worked as a primer, a beginner’s how-to manual*. If I’d have come across Letters & Lettering back then I’d have found a very good book from which to learn about constructing letterforms. The examples you can see here (and lots more on the page on Liam’s site) are lovely and clear and show the construction of, say, Trajan-esque forms. There are other examples in the book, blackletter and modern type forms, but it’s the large outlines that interest me here. This site will definitely go in the bookmarks.