This week's Cron.Weekly newsletter included a pointer to Laurens Van Houtven's Crypto 101 web site. The site includes: a download link for his pending book and a You-tube link to his lightning-stlye PyCon 2013 talk, which discusses how we got "here" and "why". Even if you don't read the book, I recommend watching the video.
I'm reading the book now. The forward indicates that the book discusses the video's topics in greater detail, as well as providing hands-on experiment so that they reader can understand how specific types of crypto are considered broken. Will make additional commentary on the book later.
One initial comment that I can make: I wish this book had been around in the 70's, when I first learned Boolean math. We went into great detail on logic circuit design (including PCB fabrication) and LVH's book would have been a nice addition to the curriculum (I have the impression that it might be a good "foundation" book for that old curriculum).
Update: LVH's blog is here.