Good luck with your book. If you don't actually get a book contract, you can publish it as an indie writer through Kindle. I have a couple of books with them. I don't think that I am going to get rich from them, but I have sold a few.
The main thing that goes wrong with horse books is that the people who write them have never seen a horse, touched a horse, or ridden a horse in person, ever. If you want to write about horses, ride. Clean stalls. Groom them. Work with an expert. Take lessons.
I would also go into the trail riding section of this forum and read all the posts on all the thread. You will pick up a lot of information.
Oh, to answer some of your questions:
1. Horses can sleep standing up
2. You do have to take the bit out at night no matter what
3. Carriage horses usually can be ridden
4. Horses need new shoes about every 6 weeks
Last edited by Celeste; 09-29-2012 at 10:32 PM.