Since several of you out there think of me as a children's author, I have to say categorically that this book is absolutely, positively NOT suitable for children or young adult readers — it's much too naughty — although regrettably I have no way of stopping you buying it if you decide to do so.
Madame de Gaulle's Penis is not, and probably never will be, available through your local bookshop, but you can order a copy from Amazon.com, Amazon.co.uk, and, more cheaply but a little slower, from Lulu.com. It might even turn up on the Barnes and Noble web site eventually. Search for it by title or author name.