This is the updated text of a TripList (about to be deleted by TripAdvisor) with some updates.
=> 1. What to see as you drive into the Valley
First things first. Drive toward the Valley, taking advantage of your early morning start to a great day. Be sure to get photos from Tunnel View and to stop at Bridalveil Fall before the crowds arrive.
=> 2. A map of the Valley
=> 3. Vernal Fall hike
First stop, a walk up to Vernal Fall. Ride to Shuttle Stop 16 and begin the 3 mile round trip hike to the top of Vernal Fall. The trail is paved to the footbridge and surprisingly steep. Continue on to the top of Vernal Fall; be careful with your footing in the spring & early summer on the wet steps. If you want more views and a gentler descent, continue past the top of Vernal Fall and take the trail to the right to Clark Point (great views of Nevada Fall) and then walk down the John Muir Trail, about 5 miles total.
=> 4. Nature Center at Happy Isles
Back from your hike, wander around a bit in the beautiful Happy Isles area. Check out the 1996 rock fall from Glacier Point above.
=> 5. Mirror 'Lake'/ Meadow and along the Valley
Continue walking to the intersection with a Valley Loop Trail and turn left toward the Majestic Ahwahnee Hotel. Even in the midst of summer you'll have fewer folks around you. Walk about 2.5 miles to the Church Bowl Picnic Area or the back of the Majestic Ahwahnee Hotel. Eat your picnic, dine at the Majestic Ahwahnee, or continue on to Yosemite Village and buy lunch.
=> 6. Lower Yosemite Fall
Continue on the same less traveled path to Lower Yosemite Fall. Enjoy the cooling mist at the viewpoint for the waterfall.
=> 7. Columbia Rock
If you still have plenty of energy and want a strenuous challenge, hike up to Columbia Rock for a great view of the Valley. This is just part of the Upper Yosemite Fall trail and is accessed near Camp 4; walk or ride from Lower Yosemite Fall trailhead.
=> 8. Sentinel Meadow, Cook Meadow, and lots of views
Instead of the strenuous hike up to Columbia Rock, how about a flat 2 mile walk through a meadow? This trail has little shade but great views. Walk all the way to the Yosemite Chapel and over both Sentinel Bridge and Swinging Bridge.
=> 9. Tired Yet?
If it's a warm day, stop by the river anytime to dip your toes. Later in the summer folks swim or float here, but be very careful in spring when walking near the fast water.
Be sure to spend some time in a quiet place just reflecting on the beauty of Yosemite Valley.
Eventually, you'll need to head back to your car. Use your feet or the shuttle. Consider stopping at Valley View for one final view of the Merced River and Yosemite Valley.