Wondering what to do on the upcoming weekend? The Friends of the Library Book Sale starts at noon on Friday at the Central Library. It continues through Sunday. If you've got kids to entertain you could take them to the East Branch at 3 pm Friday for festive snacks and craft-making with their ever-so-much-fun children's librarian Meghan Forsell. The Boston Calendar has a list of events occurring this Saturday, many Halloween- themed, others not. And if you just feel like curling up with a good book, here's a list of recommended horror novels.