FOSEL volunteers have been sorting through the many books that were deposited at the South End branch for months: textbooks and encyclopedias will be chucked but children's books, cookbooks, collections of essays, short stories, novels, science and garden books will get the nod. They will be on display for perusal and sale at Library Park this coming Saturday, May 18 from 10 AM till 1 PM when rain clouds will disappear and a special-order bright and sunny day is supposed to be delivered. All proceeds will go directly to the library staff for programming use and supplies. No early birds, please. If you need a book bag for your purchases, FOSEL's beautiful and sturdy library bags made will be available for sale at $10. Check those book shelves in your home for any books you loved but no longer need: someone else will likely love them, too.