Perch are hard to come by in Illinois in my opinion. If you find a spot keep it to yourself that is for sure. I would try maybe the Fox Chain or even Montrose Harbor for perch, but generally the bigger ones come in the fall. Shabbona gets hit pretty hard, and has a ton of structure. Make sure to stop by the bait shop and they will give you a map with all the marked structure. Right now, I would start with the deep trees around the southeast side of the lake. There is also a road bed, rock piles, and a ton of cribs to fish, especially by the campground on the north side. You will see all of the holes. Like I said, stop by the bait shop or give them a call and they will help ya out, I think they open around 8 am (late for a bait shop). Good luck