Alan Armstrong started volunteering in a friend's bookshop when he was eight. At 14, he was selling books at Brentano's. As an adult, every so often, he takes to the road in a VW bus named Zora to peddle used books. He is the editor of "Forget Not Mee & My Garden," a collection of the letters of Peter Collinson, the 18th-century mercer and amateur botanist. He lives with his wife, Martha, a painter, in Massachusetts.