coolinfographics.com has a list of data visualization tools that are available today.
Probably one of the best dataviz website is datavizcatalogue.com. It has all kinds of dataviz.
If you need an icon for your visualization, thenounproject.com has over one million icons.
Wordle is a toy for generating “word clouds” from the text you provide.
If you have geometric data that you want to visualize, use batchgeo.
Gliffy is tool to make diagrams, flowcharts etc.
If you need interactive images or videos use thinglink.
If you want to see terrible visualizations, check this out!