I enjoyed reading along with International Polar Year in 07/08, and think following along with the International Year of Astronomy will also be fun. Their site has lots to explore, including a blog called Cosmic Diary, written by a large group of international astronomers, a large selection of images as part of an Earth to the Universe project, a whole project about Dark Skies, and many other things to discover.
I think that this will fit in perfectly to the Science Book Challenge -- I'll read astronomy books as part of my ongoing challenge. I have one on hand right now that I was thinking of reading:
And to give you a bit of a laugh, not taking ourselves too seriously:
