The following are some of the best books I’ve found to learn more about Architecture.
Books for Children
13 Buildings Children Should Know(2009)
This short book keeps things simple by talking about just 13 buildings. The Pyramids at Giza, the Eiffel Tower, Sydney Opera House and Birds Nest Stadium in Beijing. There are 4 pages about each building with photographs, drawings, and some basic text explaining the building, it’s architectural style and the historical context.
Architecture Collections
Great Buildings(2012)
A beautiful book with countless great photos and large two-page spreads with visual tours. Excellent introduction. My favorite of this type of book.
World Architecture: The Masterworks(2008)
This is a very large coffee-table book with excellent photos. It is strongly biased towards diverse historic buildings from all over the world.
Architecture Field Guides
What Style Is It: A Guide to American Architecture(2003)
A very good initial exploration into different styles with useful photographic examples.
Modern Architecture
Makers of Modern Architecture: From Frank Lloyd Wright to Frank Gehry(2007)
This book is a collection of interesting, well written and detailed essays about several of the most important architects that preceded, created and followed in the footsteps of modern architecture. It is not an introductory text and uses a lot of architectural terms, but it is a great way to get a deeper look at an architect after being exposed to their work for the first time. See also Makers of Modern Architecture, Volume II: From Le Corbusier to Rem Koolhaas.
Postmodern Architecture
The New Paradigm in Architecture: The Language of Postmodernism(2002)
One of the bibles of this style, this is one of many editions of the same basic content by the same author.