The Pre-Loved Bookshop in Cannon Hall's Walled Garden currently raises around £4,500 a year from donated books.
That money supports projects including family learning, volunteering, education and wellbeing activities, as well as helping with the care of Cannon Hall Museum, Park and Gardens.
Barnsley Museums and Heritage Trust has now launched its "Bookshop Buddy" initiative.
Businesses can help by setting up workplace book collection boxes, organising book drives or becoming public drop-off points for unwanted books.
Companies interested in taking part can contact the trust at info@bmht.org.