For years the scientific method has been a linear process of finding how our natural environment works. Scientists use the scientific method to search for and find cause and effect relationships in nature. In other words, they design an experiment or interpret data so that changes to one variable cause something else to happen in a predictable way.
These days, with oceans of data available and at our fingertips, it's important to realize that the traditional scientific method no longer shows the whole story of how important discoveries are made. There have been new attempts at showing how this process works in our modern time.
For example, the chart below is from The Next Generation Science Standards and shows an expanded model for how scientific discovery happens.
Another take on this is this interactive flowchart by The University of California Museum of Paleontology at Berkley. Note that each of these new models include an important aspect: communicating your discoveries, so they are a good step forward in that regard.
Just as it does for professional scientists, the idea of a 'scientific method' will help you to focus your science fair project question, construct a hypothesis, design, execute, and evaluate the results / data of your experiments.