If you really want to do magic a disservice, donate your magic books to your local library. This is what happens in Houston, and other reports indicate the same thing happens elsewhere. If you do not also donate adequate funds to house the books, display them and conserve them, first, most of the pamphlets will be given away. These are usually "worthless" things, anyway, like all the Marlo Revolutionary Card Technique series and the Goldstein color series. And, of course, there are all those "worthless" pamphlets by Dai Vernon. At least, that's what these librarians think of them. From their point of view, though, they need to have them bound and conserved, and that may take more money than they are prepared to part with.
Most of the periodicals will be thrown away, or, if bound, sold at their remainder tables. The bulk of the books will remain in their basements until someone sees fit to catalog them.
Instead, if you are married, leave instructions with your spouse as to how to maximize the impact of your library. Give her some leads as to who might want to purchase your treasures. Or find a local, budding amateur and make him a very happy heir.
I can attest to Byron Walker's generosity in sharing information with people. He is largely responsible for my monograph on the paddle.