If you want to do Pt/Pd, you should have both the Arentz book AND the Sullivan/Weese volume on your shelf. Dick Arentz' book is very helpful for diving in to the deep detail and the profoundly technical, if you want to go down that route. Not necessary, but it is always a good refresher to go back and see where you can improve on your process. Having seen Dick's prints in person, I put his work as a gold standard against which to measure. The Sullivan/Weese book is also a classic, as it makes the process simpler and less intimidating. I had the good fortune to learn from Carl Weese, and he made it very straightforward in person - it really is not any more complicated than silver printing - about the same number of overall variables, just different.
I'll put in another mention for Coming In To Focus, the Christopher James book, the Farber book, and also, "Primitive Photography" by Alan Greene. Another book more folks should have is The Care of Photographs (I think thats the title) by Sigfried Rempel. It is always a good idea to have a reference for how to handle different kinds of photographic materials, especially if we collect antiques. And who among us doesn't have at least one tintype or dag floating around the house? And those old cabinet cards with the albumen prints of our essentially anonymous great-great aunt whatserface?