August 21st is the deadline.
http://therealljidol.livejournal.com/483433.html for more info.
I would suggest diving into your archives and figuring out what you want to submit.
For those who are interested in the first book: http://www.amazon.com/Idol-Musings-Sophie-N-Childs/dp/0473151006/ref=sr_1_1?ie=UTF8&qid=1312978716&sr=8-1
If you were in it, and are eligible for a discount, I'd suggest contacting the editor directly.