A short list of various websites with Inkscape tutorials.
Whitescape, a group dedicated to Inkscape, an open source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.
Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.) and great care is taken in designing a streamlined interface. It is very easy to edit nodes, perform complex path operations, trace bitmaps and much more. We also aim to maintain a thriving user and developer community by using open, community-oriented development.
Official tutorials: Inkscape.org
Guide to a Vector Drawing Program e-book: Tavmjong.free.fr
35 Tutorials to create amazing Vector Graphics: Speckyboy.com
Inkscape tutorials web blog: Inkscapetutorials.wordpress.com