First thing to do is to look up Lender-owned properties on MLS and see who is listing them. Then, call, and introduce yourself, and ask if they have any advice. Most will be happy to tell you exactly what is required. Most agents don't realize that REO agents frequently bear the cost of cleaning up, preparing for showing, maintaining and securing the properties until reimbursed (not always promptly) or sold. It is a property management business as much as a listing business. So, be sure that you can afford to carry that expense for several months before you get paid. You should also develp a taste for evicting people who have just lost their homes.
Like many things in Real Estate, what looks easy isn't. I have the greatest respect for REO Listing Agents, but I wouldn't do that for twice what they get.