The Wooster Friends of the Library’s annual Summer Book Sale will be held tomorrow through Saturday at the library’s book cellar, on North Market Street.  Hours on Thursday and Friday will be 9am-4:30pm, while hours on Saturday will be 9am-2pm.  Saturday is bag day, meaning all books that a person can fit into a grocery bag are only $5.  The sale, by the way, will also be open tonight from 5-7pm, but only to Friends of the Library members.