I have recently been cited for not knowing what Data Visualization means. While I can not confirm nor deny, I am passionate about the subject. Most of what I know, has been learned from Stephen Few in his three books on Data Visualization: Show Me The Numbers, Now you see it and Information Dashboard Design. They are excellent works, and easy to learn simple and advanced material from. 
I like his work and examples so much that I created duplicates of them using wijmo. You can see proper visualizations using wijmo here (please ignore the pie chart). 
I have recently had the pleasure of speaking on the Data Visualization in Sweden at DevSum. The event was in Stockholm and was absolutely beautiful. I had fun giving this talk and added some humor in as well. The goal of this presentation was to educate developers about:
- The importance of good Data Visualization
- Good & bad practices
- Tools in HTML5 to build visualizations
Here are my slides from the presentation. I hope they help you understand Data Visualization a little more.
Now that you are slightly more educated, try taking Stephen Few's Data Visualization IQ Test And now to continue my quest to figure out what Data Visualization actually means...
