This trip starts out of Yosemite Valley floor and is about 9.4 miles round trip and 3300ft elevation change. This is a difficult hike. The GPS trail on this hike is off on the trip up, but accurate on the downside trip.
Parking is available on the side of the road, but you will have to compete with people stopping to look and enjoy the scenery. There are no facilities here so be sure you do what you need to do before starting or you will have to be a bit more creative ;). Be sure to bring PLENTY of water. This trail is a combination of shaded area's and sunny area's. It was about 75 degree's when we hiked but it felt a lot warmer.
Basically, this trail is up, up, and more up. The views of the valley are spectacular. The view of course changes the higher you get. Great views of Yosemite falls, Sentinal Dome, El Capitan, Half Dome as you climb up. The end of the trail puts you at the visitor center at Glacier point.
Of course, the views of the valley, Half dome, and Nevada Falls, as well as the back country are great. (You can drive up here, but that would be missing all the fun). There are facilities available and water (even ice cream).
The trip down, while not as strenuous as the trip up, requires your attention due to the decomposed granite. The trail can be very slippery (I call it walking on ball bearings).
Bring lots of water. Walking sticks might be helpful on the trip down.