I gave my niece a book that was my favorite when I was a teenager, and I wanted to pass it along to her. I also wrote on the inside front of cover how much this book meant to me when I was growing up and hoped it would bring her inspiration. My husband thinks that giving a "used book" and also writing in it, was improper. He also stated that only authors were to autograph or write something books. Is he right?
Don't be worried. Giving a book that you had valued was a very thoughtful gift. Also, inscribing a note inside the book is a nice gesture, too.
Anyone can put an inscription in a book, not just authors. Often, authors or illustrators of the book sign their name on the title page of the book.