Distance: 7.6 miles (12 km) round trip from the Lower Yosemite Falls
trailhead; 9.4 miles (15 km) including Yosemite Point
Elevation at trailhead: 3,967 feet (1,347 meters)
Elevation at top of Yosemite Falls: 6,526 feet (1,989 meters)
Elevation at Yosemite Point: 6,936 feet (2,114 meters)
Elevation gain: 2,600 feet (790 meters) to the top of Yosemite Falls; 2,969 feet (890 meters) to Yosemite Point
The blue line at the bottom of the map marks the route from the Lower Yosemite Falls trailhead to the Upper Yosemite Falls trailhead. The Lower Yosemite Falls trailhead is probably where you'll start the hike, since the free shuttle buses stop there and it's the easiest place to find the route to the trailhead proper.
The green line marks the official trail to Upper Yosemite Falls. That's not just a really thick line at the bottom of the trail - it's switchback after switchback after switchback. You'll get warmed up in a hurry on this hike. The trail goes all the way to the lip of the upper falls, marked by the purple pushpin.
The yellow line marks the extra-credit hike to Yosemite Point. It's short but climby. If you've got energy and time to spare, it's worth the effort for the views of Half Dome from here.