You could start with today's Google logo.
Charles Darwin is being celebrated around the globe for his contributions to biology, the Darwin Day website lists over 650 events in 44 countries. There have been countless newspaper and magazine articles, several TV specials (3 on Science Channel tonight), some podcasts (here and here, for example), and there will be, I'm sure, thousands of blog posts (not unlike this one).
Why celebrate Darwin? I think, at least in part, it has to do with the fact that he has become the "whipping boy" of choice for the "creationist" crowd. Why not revile Charles Lyell, the geologist who told the world in the 1830's that our planet was more than 6,000 years old (a folly based on nothing more that the OT "begats" tallied up by a 17th Century bishop). It really is probably because evolutionary theory takes away the conceited view that we humans are special in the universe, something that geology really doesn't do.
Darwin didn't have everything right, but his work inspired thousands of biologists over the past 150 years (this year is also the sesquicentennial of the publication of On the Origin of Species by Means of Natural Selection). Darwin knew nothing of DNA, yet the science of genetics expands and improves upon his original ideas. Paleontologists, despite the rants and raves of creationists, have found numerous transitional fossils (extensive discussion here).
Remember: "Nothing in Biology Makes Sense Except in the Light of Evolution" (Dobzhansky, 1973).
For the rest of the day I am personally going to celebrate the wonder and awe of this world, and, in fact, the entire universe, made all the more amazing to me by the work of people like Charles Darwin. (I'd celebrate by going birding if I could, but work and the heavy snow falling right now are getting in the way.)
Happy Darwin Day!
(My rant is below the fold, if you dare)