I haven't attended any of the ebay conferences, but I've heard that they are very good. ebay itself is happy to answer some of the questions he might have. Not only should he look at estate sales, etc., but wholesale items that he can then turn around and sell at a small mark up that keeps it a good ebay buy vs. retail.
One of the best things he can do to begin is just spend time looking on ebay to learn what people are looking for and if he is near any kind of outlet stores - say Pottery Barn, Le Creuset cookware, Linens & Things, any type of outlet store where he can pick up quality items with a slight irregularity, he can easily make a profit by selling them again. Hope that helps!
He and his wife have two small boys. When he got laid off, his wife went to work and he's been staying home. But she doesn't make as much as he did.
If he could make up the difference between the two, that would definately help. They're extremely frugal, but the savings are being eaten up.