get in the box of short sales

Hi everyone…
This forum is somewhat of a gold mine, thanks for all the participants.
I start from scratch and have only time on my side, plenty of it. Of course i have a ton of questions on short sales but one especially, the starter one :
how do you find pre-foreclosure houses ? Talking to banks ? through a broker or realtor ? To lenders-mortgage brokers ? on those websites that gives you listings ?
The rest of the process is pretty clear until i get some unexpected difficulties of course.
Thanks for any help.
an eager newbie

Try the county courthouse. Notices of default are a good start.