What I did:
I drew for the smaller prizes first and then put those winners' names back into the hat for the laptop. I decided that if the person who won the laptop also won one of the smaller prizes, I'd redraw for the smaller prize. It worked out that I didn't need to redraw. Here are the winners:
Copy of CROPS AND ROBBERS or bookstore gift certificate equal to the retail value of the book:
$20 Bookstore Gift Certificate:
Laptop GRAND PRIZE:
Thank you, all, for playing. I ended up with over a hundred entries which far surpassed my expectations. And thanks for all your kind support.