Here's how you can get involved:
Kid/YA Authors and illustrators (and publicists, too), if an independent bookseller carries your traditionally published books, ask if they'll gift-wrap and ship signed or personalized copies. If your bookstore agrees, send an email with the title of your most recent book, your name, website URL, publisher, genre, suggested age of reader, along with the indie's name, URL (if they have one) and telephone number.
Tell Mitali if you're willing to personalize for each recipient or if the bookstore is offering generically signed stock. Add a brief two- or three-sentence blurb from an established review source and attach a small .jpg of the book cover (less than 500kb) to the email.
See the site.
There's some great stuff there already (including books signed by Mitali, Judy Blume, David Levithan, and Rebecca Stead).