I stumbled upon two interesting links via this blog that I follow:
1. A PhD comics take on buzzwords in scientific literature.
10 worst data visualizations in scientific literature. Some of it may be nit-picking, and I am sure like all top-10 lists (or US News college rankings, for that matter) this list is flawed in terms of the "top"-10. But it makes for an interesting read nevertheless.
The "discussion" on each graph is enlightening, particularly since I must have committed some of the same mistakes myself.
One interesting thing I learned was how bad pie charts were. Apparently, we are much better at comparing lengths than areas. I never knew that.
There are some good links on how to present data wisely at the bottom of this link.