If the bookstore is non-profit and the workers are volunteers, I don't see a problem with a church selling edifying books on the Lord's Day...

__________________
Mason
Member, Redeemer Presbyterian Church (PCA)
New York, NY

"Come now, and let us reason together," says the Lord, "Though your sins are like scarlet, they shall be as white as snow; though they are red like crimson, they shall be as wool." - Isaiah 1:18