Perch like cover, any cover, they can be spooky on busy club waters or commercials and do move to deeper water if disturbed.
You will know what type of water you are fishing, but I would always try the margins, snags, trees and bushes first, if there are any structures, give them a go, as a rule of thumb, Perch tend to be most active in low light condition, dawn and dusk, but on some waters will feed throughout the day !!
Bob