Once you get used to clipless, you'll wonder how you managed to deal with the traditional cage system. Practice clipping in and out, preferably on a soft surface. You will be surprised how natural disengaging you foot from the pedal becomes.
Most pedal systems have an adjustable release tension. You may want to experiment with a lighter tension until you feel comfortable engaging/disengaging.
Just my 2 cents....coming from someone who HAS failed to un-clip and took the infamous tumble!! It was a long 2 seconds!
Dan