"The Machinery of Life," by David Goodsell, is an illustrated journey through cells and proteins and macromolecules - at scale.
What I like about the book is that it attempts to show what it really looks like if you're the size of a molecule - the crowding, the relative sizes, and so on.
It's a really fascinating book for someone like me who has his head in the (molecular) clouds. :-)
There is a review of the original edition (PDF). A nice phrase from that review was "cellular numeracy," referring to the way Goodsell places things in scales, making us realize the relative sizes of molecules and cells.
At the iGEM Jamboree I saw a color image from Goodsell. After searching a bit, I now know that there is a color edition of the book (just out in 2009?), updated with new molecules, too. You can see more on Goodsell's own pages at Scripps.*
I highly recommend this book for anyone messing with molecules, to get a good idea of what the macromolecular landscape truly looks like.
*It's a shame that the Scripps pages are so 1999-ish. The site needs to be more visual and more up to date.