Today two new tutorials were checked in: Calligraphy and Tracing (in Help > Tutorials).

Calligraphy tutorial describes in detail the capabilities of the improved Calligraphy pen tool. A brief history of the art, parameters of the tool, useful tips, and many examples from simple strokes to complete lettering projects.

Tracing tutorial explains all the options and parameters of the Potrace interface for bitmap tracing, with tips and examples.