I'm currently reading Darwin. I'm just starting to study evolution and figured it would be a good place to start. I'm finding it cumbersome, and still have 300 pages left to go. It's a good thing natural selection can be summed up nicely by others in half a page, so I knew the basic theory before going into "the Origin of Species".
Over the years, I have read the Bible cover-to-cover once, the entire New Testament a second time, and have skipped around and read parts quite a bit.