Scientific discovery isn't as simple as one good experiment. The weird and wonderful history of cell theory illuminates the twists and turns that came together to build the foundations of biology.
Learn more about how cell theory was established and how the scientific method works: http://science.howstuffworks.com/innovation/scientific-experiments/scientific-method4.htm
This timeline will help you visualize every step of the history of the cell theory: http://www.timeline-help.com/the-cell-theory-timeline.html
A fun way to learn more about cell theory -- The Cell Theory Song: http://www.youtube.com/watch?v=KuJqqiATlqw
More science education resources from this lesson's educator, Lauren Royal-Woods: http://www.bal.henderson.k12.nc.us/teachers/lroyal-web/