Complex sentence: Advice and help with recording and cataloging the books was generously provided by Prospect Heights Library staff and the Woman's Club of Prospect Heights whom had very recently established the Prospect Heights Library District and their experience with forming a publicly supported library district was greatly appreciated.
Split into simpler sentences: Advice and help with recording and cataloging the books was generously provided by Prospect Heights Library staff and the Woman's Club of Prospect Heights whom had very recently established the Prospect Heights Library District. Their experience with forming a publicly supported library district was greatly appreciated.