If your research or assignment involves the collection of data, you will need to both figure out what your data means and be able to explain it accurately to your readers. Analyze your results mathematically, using mean, median, mode, range, percentages, etc. to find explanations of your results, and then present your findings visually using charts, graphs, and other visuals. Below are some data analysis and visualization tools:

Simple Interactive Statistical Analysis (SISA) -- An online tool that you can use to perform statistical analysis instantly. Read an overview of each procedure (there are a lot!) here.
VassarStats - An online analysis tool with great instructions included.
Excel Charts - Step-by-step charts using Excel, from Microsoft Office.
Many Eyes - A site that allows anyone to upload data, visualize it, and talk about discoveries with other people.
Power View/Excel 2013 - Quickly create a variety of visualizations, including all kinds of charts, maps, and combinations.
US Census Data Visualization Gallery - View a variety of data visualizations from the Census Bureau (lots of ideas here!).