Sherman Falls is GORGEOUS. And it's pretty easy to get to. It's one of those falls that has a very well-maintained path, and the path is literally a minute long. It's right at the intersection of Old Dundas Road at Lions Club Road; if you turn right onto Lions Club, there is room to park on the side of the road. If you also want a bit of a longer walk, or to see a couple falls in one go, you can park at Tiffany Falls, on the lefthand side of Wilson St., about halfway up. Across the street is an entrance to the Bruce Trail, and you can follow that to Sherman Falls.
I hadn't been to Sherman Falls in probably around 7 years, after a traumatic incident disturbing a wasp's nest while on the ledge of the falls and was unable to climb down. I've gone a couple different times this year though, in the winter and the summer - I have also discovered that that same wasp's nest is there, so if you're wanting to climb up the falls, be careful!
(Edit: for another hike including Sherman Falls, check out this post!)