This tutorial is meant to give absolute beginners a detailed understanding of using and applying colors and gradients in Inkscape, and the different options available to you when working with object color. This tutorial goes very slowly, and covers basics, so if youâ€™re above beginner-intermediate level, this will probably bore you to tears. http://www.kendraschaefer.com/2009/06/inkscape-tutorial-color-and-gradients-for-absolute-beginners/#anchor
I for one was not bored.
I am finding many places that tell about the gradient, but this one as promised does give the absolute beginner a good understanding of colors and gradients.
Of course I am finding understanding and applying are two different things.
The site also offers several other fun things to try.....that are way above the beginner.