Source of Knowledge: Graphic Design, A Concise History by Richard Hollis (Thames & Hudson)

As its title reveals, this book is a concise history of graphic design. In my opinion this is a very informative and very inspirational book. Unlike bad history books, this one is loaded with photos to accompany the texts, alas, with rather small B/W photos.
Actually we also had this book as a textbook at our graphic design history class at the university.
Some typical spreads include:I bought this from amazon.com.