Weeding my bookshelves (and book boxes)

As much as I hate to do it, I've finally decided that I have to give away some of my books. I no longer have room for them, especially as the kids get older and their things take up more and more space in our tiny house. I'll keep my favorite ones, of course, but I plan on donating most of the others to the library or to the Salvation Army.

Have any of you ever weeded your bookshelves? I feel like I'm giving away my kids...