I know what you mean about the books! I finally broke down and went through each one quickly, asking myself if I was still the quilter I was when I bought the book 30 years ago? and if not, or I had mastered the info in the book or the examples in the book were repeated in a thousand other places, I put the book in the donation bag. I haven't looked back and my library is now very timely and great fun to go through. At some point one has to let go of something.
Otherwise, you might take all the old books you aren't looking at but want to keep and put them in small bookcases and hide them behind a couch or something in a corner and pull out the furniture when you want to get to one of them. Keep the current books handy on a shelf in your quilting room. Meanwhile, have you utilized the wall space in your quilting room? Look up! is there a place for a board and bracket bookshelf...go for it!