Very simple, point it at the sun and hook your phone to the port marked A for Automatic and it charges pretty quickly. The Auto port is so if a cloud passes by and charging stops, it will reconnect without any effort on your part and pick up charging where it left off. Great kit, well built and made in the US to boot.
Amazing little panel that packs a punch. In full sun I charged 4 2300mah AA batteries that were completely dead in 3 hrs. I have recommended to all my friends.