Run through the book and you will have a solid foundation to start playing around on your own for basic visualizations and charts.
http://shop.oreilly.com/product/0636920026938.do
This was also posted on HN a while back:
http://code.hazzens.com/d3tut/lesson_0.html
d3 is not dependant on jquery and covers a lot of the same basic DOM manipulation. You also need to learn some super basic css to theme things.