Yellow Perch are relatives of the Walleye. Excellent table fare too. Their scales are small, and they're a bit tough to get those scales off, plus those spiny fins & sharp gill covers can inflict some nasty wounds. I used to keep them to eat, but now usually release most of them. IMO, they're better for eating when caught in the colder waters of early spring or winter than they are after the waters warm up.
Here in MD we have White Perch too. No relation between the two. White Perch are actually related to White Bass & Striped Bass. They're a lot of fun on flies as well, and are one of my favorite fish for eating. White Perch also are not picky about flies.
Here's some flies I like to use for both types of perch. Most are tied on size 4 & 6 hooks, a few on size 2.