Anybody familiar with the views UI can use the chart module to create charts without coding PHP snippets, as one typically does when using the Chart API.
So site building knowledge is sufficient to create charts using Views, you don't have to be like an experienced Drupal developer (who probably would rather want to use the Chart API instead).
All that's needed to transform tabular data into some type of chart, are a few mouse clicks to configure the chart settings (= various options of the chart to be created), using an intuitive User Interface. After saving these options, the line chart gets created automatically.
While waiting for the step-by-step instructions to get added here, refer to #1164882-4: HowTo about Views integration (still about D6 but D7 is similar). Anybody interested in integrating those instructions in this docu page here? Chart HowTos may include some more links about creating charts using views.
Tip: The video mentioned in #1164882-6: HowTo about Views integration is another great resource! Starting from around 10:15 the view fields are added and starting from around 12:15 the chart module is added. The (tiny) bug mentioned there is now detailed in #1117002: How to make a 3D Pie chart work with views. Thank you linclark for this video!
Note: If you're aware of other videos related to the chart module, or you created one yourself, please update this page and add it here also.