great reference
This book is one of my favorites as far as type books. It is a great reference and the layout is easy to navigate.
Great Overview of the 20th Century
This is a great book containing a very good overview of the 20th century changes in typography. It covers everything from pre-art nouveau to postmodernism. A good resource for any design or typography library. My only complaint is that Blackwell waxes a bit too poetic on 1990's postmodernism. Also, they used a tight-fitting Helvetica for the body copy - so reading it takes some effort.
This is certainly worth having in your collection.