I think you should pick out the ones you think still look good and read them. If your tastes have changed then give them to someone who wants to read them. A good book is a terrible thing to waste. *GRINS*
Well the only book signing experience I have is a book I won on twitter called Sucks To Be Me by Kimberly Pauley. Wonderful woman. She signed the book she sent to me. I'd love to get more books signed though. ;-)