One of the more popular beaches along Shuswap Lake seemed to be located at Shuswap Lake Provincial Park. This is a park located along the north-western shore of the lake, essentially across the lake from the town of Sorrento.
While there are forested trails here, I think the major attraction is the beach. There are also camp sites (open from July to Labour Day) and a boat launch.
The Margaret Falls are over 200 feet high and cascade into Reinecker Creek. The walk/hike is an easy 10 minute self-guided nature walk in a beautiful gulley with large trees and cliffs looming above you, and a cave near the base of the falls is large enough to hold 2 or 3 adventurous explorers.
We took lots of picturesque photos. We then walked back along the trail into Herald Provincial Park.
Address: Located in Tappen, 10 miles north of Salmon Arm
Directions: The Margaret Falls are located across from the Herald Provincial Park day-use area (see below), 9 miles (14 kms) east of the Trans Canada Highway on the Sunnybrae Canoe Point Road.