Evelyn,
Welcome!!! My Dh and I are pretty much in the same boat as you...no bio children, but are excited to adopt our baby! We haven't started our homestudy yet, but my plan is the same as yours, to start the extended protocol after homestudy and approval.
Most of my info has come from this website and the amazing ladies here. I also found a LLL leader in my area who bf her adopted babies, I wanted to make sure I have a good support system when the time comes! Good Luck finding info!