The book explicitly contains a tutorial section that describes dynamic variables, non-local transfers of control, and lexical closures - the three building blocks that allow for construction of a condition system.
The part that comes afterwards constructs the condition system piece by piece, function after function - and only after we've constructed something from scratch, we draw parallels to relevant parts of the condition system. There's also a short tutorial for macro writing as an appendix, since we will write some macros as a part of the condition system.
Overall, this book should be able to introduce a programming into using the Common Lisp condition system. For the very basic basics, I will still want the reader to start with Practical Common Lisp, but once the reader knows the basics of syntax, evaluation rules, and basic data types in Lisp, they should be able to follow the book from the beginning.
Or, in other words, one shouldn't read a book about handling exceptional situations if one doesn't understand what are exceptional situations or why one would need to handle them.
So, I'll read your book after working through both of the others.
(Also, Common Lisp isn't a functional language. It's a multiparadigm one that often gets the label of being a functional one because Scheme and Clojure are really functionally oriented.)