The drive from Grant's Grove Village to road's end in King's Canyon NP is mostly easy driving. There is a curves-filled portion early in the drive after the Princess Campground. There are numerous Viewpoints along the road for photo opportunities. I stopped at Boyden's Cave and purchased the tour, which was a bit underwhelming. I believe it is a private concession vendor and not run by the NP or NFS.
The Cedar Grove Visitor Center will be along the left further down Hwy 180. The bridge was under repair in August 2013 and you cannot reach the store or lodge from Hwy 180. After passing several campgrounds, there is a waterfall on the right reached by a 0.3 mile stroll. It's not a hike rather just a short walk. Stop at Zumwalt's Meadow and hike around the Meadow. Pack a lunch, since eating along the trail in a quiet forest was wonderful. The hikes at Road's End will be longer, since I could not find any short trails here. Many were playing in the river, and jumping off Muir's Rock (sic). Backpacker food storage lockers are here near the parking area on the north side. Bring water.