If you're both new I'd recommend "The Topping Book" and "The Bottoming Book" by Dossie Easton and Catherine Liszt, they both presuppose little or no experience or knowledge of the scene and are well illustrated. After you've gone through those I'd recommend "Screw the Roses, Send Me the Thorns" by Philip Miller and Molly Devon as a very thorough overview of the various aspects of the scene. All are readily available through Amazon. Something never to forget is that a D/s relationship is still, first of all, a relationship and that the normal rules will still apply, it's essential that all parties needs be met and that open and honest lines of two way communication always be maintained.