The Providential Gardener Bookstore has selections recommended by Audubon Society of Rhode Island and garden clubs, as well as books about gardening & lawn care. It's an Amazon store, and there's always a link to it in the righthand sidebar.
Remember that the Audubon Society of Rhode Island has book clubs every month. In November 2007, the book for discussion is When the Rivers Run Dry. For more information about the Audubon's environmental book clubs, search the posts on What Grows On in Rhode Island. The November 2007 book club press release gives times and places of the clubs.