The signed book has become the pinnacle of book collecting. It combines the aspects of two different hobbies, books and autographs, into one huge field of interest. As with any new specialty many questions arise: where should it be signed; what about inscriptions or dedications; what's authentic; and much more. You may find some of these questions and answers helpful as you move into collecting signed books.
We don't suggest personalized messages for a couple of reasons. First, unless you have the name of the person to whom the book is personalized, it can actually devalue the signature. Second, getting signatures is tough enough, without asking them to write even more.