My good friend J.C. Cannon has written the book on Privacy aimed squarely at developers, as well as IT folks. While I, and many others, focus on security, J.C. and his team address privacy issues. I think most people consider the two disciplines kinda the same, they are quite different, and I would urge you to get a copy of the book if your application deals in any way with private data.

http://www.amazon.com/exec/obidos/tg/detail/-/0321224094

BTW, J.C.bought me a very nice bottle of Cloudy Bay 2003 Sauvignon Blanc recently. I'll open it in nine months. Yum, yum! And no, I'm not gonna share it with anyone but my wife. So don't ask!