It may have been mentioned earlier in this thread or some other thread, but this online novel is quite possibly the best example of IB I have read:
http://www.jekyllsdaughter.com
The prologue has a great example. The book then starts on the buildup, but around chapters 11 to 12, she starts actually transforming and it follows the rules pretty much verbatim! Heck if you check the list I made on page 11 of this thread it has all 6 things that cause it to qualify, and none of the items that would disqualify it.
I have read up until chapter 14, and there is no actual intercourse described, but it is heavily implied (certain areas aching for example). Though not quite safe for work, the novel is relatively tame as far as sex goes, though there is implied violence which I'm sure picks up later.
http://www.jekyllsdaughter.com/read11.html
You can use this link to skip chapters ahead, navigation is a bit weird.