Bill Bryson's
A Short History of Nearly Everything (2004) is a light-hearted but data-filled romp through the history of science, tackling everything from astronomy to climatology to paleontology to biochemistry to geology and, well, nearly everything in between. This is not a ground-breaking scientific work, but a good basic text for the interested non-scientist, with a nice big bibliography at the end for anyone sufficiently interested in a topic to go off and explore some more.
Bryson typically visits with experts in the various fields he touches on in the text (e.g. Richard Fortey, Ian Tattersall), and complements those reports with anecdotes from the scientific literature, pulling it all together with that distinctively dry Brysonian wit.