As a matter of fact...
It is a long and difficult process to take, but if you do it a little at a time, you will be able to enjoy the process. In my opinion, that is the main word you should remember, enjoy.
You have come to the right place to ask questions. Please feel free to do so.
As for books, I have a series of books starting with how to boot all the way to USB, GUI, File systems, and as you asked, the ATA and ATAPI disks.
Have a look at the page listed below.
Thanks,
Ben
http://www.fysnet.net/osdesign_book_series.htm