Every few days I pick up "A Brief History of Time" by Stephen Hawking and read a few more pages. Let's face it, I'm not going to be able to just sit down and read that sucker cover-to-cover. I tried it once, and then my brain exploded.
I've also just started "Cryptonomicon", by Neal Stephenson. I expect to finish somewhere around my 40th birthday.
And "World History for Dummies". I've always sucked at history. I was legitimately proud of myself for getting through college without taking one history course (except art history). Now I regret it. I have this huge hole in my knowledge base, and I want to fill it.
Most interesting thing I've learned from that book: "Czar" and "Kaiser" are derived from "Ceasar". Neat, eh?