If your having trouble catching smallies try using a 1/4 ounce jig with a 3 or 4 inch chartreuse or white grub on submerged rock piles. Drop shots work well too.
Walleye fishing was very bad in early June and my guess would be deeper water about 15-30 and rocky or mud bottom for September. But for smallies they like rocky ...more islands and shore lines. Anything from 10-4 feet. Also weedy edges will hold them. Using jigs with gulp or crankbaits work great.