I'm not a practitioner of wet plate myself, but I am an admirer of the art, so I will recommend you a book that is about just that: "The Antiquarian Avant-Garde: The New Wave in Old Processes." By Lyle Rexer, featuring a slew of artists like Sallly Mann, Jerry Spagnoli, or Chuck Close, who have started to work with collodion, daguerreotypes, cyanotypes, etc etc.
The book is organized by process, so you can sample the collodion artists, then the dag ones, etc. Reproduction quality is outstanding, and there are tons of great thinking in the featured works. Interviews with the artists, some technical and historical notes. No formulas, but plenty of soul.
PS: The only copy I see on Amazon right now sells for $300+ but that's probably another greedy bookseller. This book sells for about $50.