Check out these very cool data visualization resources provided by Portland State's Library Newsletter (page 3). My favorite is the "periodic table of visualization methods," but all of the resources listed are incredibly neat.
This is just in time for me personally -- I will be presenting on data visualization in March or so (a virtual seminar!), and need to brush up and create a really awesome presentation.
And besides the presentation, I am increasingly seeking to incorporate data visualization in my reporting. My right-brained development colleagues readily absorb information presented pictorially, whereas big Excel spreadsheets of numbers tend to leave them cold.