FlowingData has compiled a great guide on nine different methods to visualization proportions (pie, donut, nightingale, etc), giving you when to use and when not to use the various methods.
With all the visualization options out there, it can be hard to figure out what graph or chart suits your data best. This is a guide to make your decision easier for one particular type of data: proportions.
Maybe you want to show poll results or the types of crime over time, or maybe you're interested in a single percentage. Here’s how you can show it.
via 9 Ways to Visualize Proportions – A Guide | FlowingData.
