Follow the scientific method.
1. determine a problem or question you want to investigate
2. Develop a hypothesis
3. Design an experiment testing the hypothesis
4.Conduct the experiment
6. Come up with a conclusion based on the data you collected
The charts and graphs belong with the data collection
Take pictures while your conducting the experiment and have a journal where you talk about what you're doing, what you think might happen, why certain things are happening, ect...