A colleague of mine introduced me to this great resource - a 1923 edition of P's and Q's - A Book on the Art of Letter Arrangement, by Sallie B. Tannahill. (A former teacher of lettering at Columbia University and a friend of Vojtech Preissig – the Czech typographer and book designer – whose work gets sampled frequently throughout the book.)
The goal of P's and Q's is to show the infinite variation and approach to letter design through an artistic lens via examples. In the introduction Tannahill states, "Well-selected letters, drawn with force and quality, arranged in good proportion, tone and color, and grouped . . . may be as fine and as complete as (any) design." My version of the book is badly in need of repair (notice the 'discard' stamp on the inside cover,) but I still posted scans of the entire Part I (chapters 1-4) on flickr, here. If there is enough demand, I'll post the other Parts. I hope you enjoy this resource as much as I have.
Thanks for all the feedback. I'll post the rest of this beauty in the next few days. In the meantime, check out Bob Dylan's Theme Time Radio Hour on XM today - it repeasts all day today. It's a great pick-me-up, even if you're not a huge Dylan fan. So good.