From the eastern entrance you'll climb 2 miles to the Liberty Cap formation. The trail is rocky and steep; it is not one for the faint-of-heart! Round trip from the east entrance to the formation is 4 miles. If you enter from the Monument you'll have a longer hike but with less elevation gain/loss.
To reach the eastern trailhead follow Hwy 340 west to Redlands Parkway. Turn left and follow S. Broadway past Meadows Way. Turn left at the next road, Wildwood Drive and follow this around to the trailhead. There should be signs. The upper entrance to Liberty Cap is located in the Colorado National Monument.
http://www.tripleblaze.com/trail.php?c=3&i=5821