[jsfowler]

First, I would look for a video to watch (Bill Nye has a good one). When I teach photosynthesis, I use a powerpoint and break everything down into managable pieces. I use a chemical equation:

water and carbon dioxide in the presence of chlorphill and sunlight yields oxygen and glucose

I always teach photosynthesis and respiration together so we can discuss how they are opposite processes. We discuss the carbon dioxide/oxygen cycle and draw diagrams.

My advice for teaching this concept is to use hands-on materials (look at a plant cell under a microscope and identify chloraplasts, observe what happens when a requirement of photosynthesis is deprived, etc.), Bill Nye video, and diagrams (chemical equations, CO2/O2 cycle, venn diagram, etc,) I think the students understand it better when you include respiration as an opposite process.