LispForum

Not sure where to find an 'accounting example' tutorial, if you mean that. There are a couple of good books, like Practical Common Lisp. this thread lists a bunch of other books, though not all as suitable.

You could, for instance, make what you say with hashtables(make-hash-table,gethash) and structures(defstruct make-... etc.) you might want a registered-book structure, because each type of book is there in some about.