To get to the trailhead: After entering the park, keep driving along the main road until you see signs for The Windows Area (just past the Balanced Rock and a little over 9 miles from the Visitor Center).  Follow this road until it ends in a parking lot and you see the arches to your right.

The trailhead is obvious and you can decide to either go left or right to begin the hike.  I decided to start to the right which will take you past Turrent Arch first.  After taking some pictures the trail will then take you to the South Window Arch and the North Window Arch.  Once you've taken your fill of photos, continue on the trail and before you know it you'll be back at the parking lot.