Cannon Beach is a great beach for perch because there are a lot of natural features that the other North Coast beaches typically lack. It is also steeper than some of the other beaches in the area, making it easier to reach the fish. I'd focus my efforts around the area of beach south of haystack rock, including around the numerous rocky outcrops that are found down by Archcape/Arcadia beach. Although they are "surf" perch that live quite happily in a sandy environment any sort of rocky feature is a magnet to them. Needless to say the sandy areas are also excellent once you find the fish. My usual tactic is to start at the beach area right by Tolovana Inn and work my way down, taking extra time to fish the rocks as I come across them. Also remember that you can't fish around Haystack Rock itself, as it's a protected marine garden. The standard rigging and bait applies here; I usually use a carolina rig with Gulp! or a standard two hook rig with the same bait. Like other perch areas, incoming/high slack is the best time tidally although if it's really sunny and clear out I'd wait till the evening so the fish get less spooked. Also remember to release the big females; the surfperch spawning season is coming up and lots of fish should be full of their young.
Good luck out there! Hope I was of some help.