In this tutorial, I'll introduce you to PHP/SWF Charts, a great solution for building PHP- and Flash-driven charts. PHP/SWF supports a wide variety of charting formats, including bar, candlestick, 3D columns, pie, 3D pie, and advanced charts such as scatter, polar, and composites. See the maani.us PHP/SWF gallery for a great compilation of examples.
They focus mainly on a bar chart to keep things simple. They show how to install the software (dead easy) and how to create a simple first chart complete with a graphic to illustrate. Flat charts are nice, but they show some of the real power of the library by transforming it into a 3D bar graph, giving the columns some depth and all it really takes is changing the chart type.