While not a public library, Columbia University's Avery Architectural & Fine Arts Library is one of the best in the world and their website contains information for students and architects that anyone can access.
Finding Books and Ebooks
Find Books & E-books in the Library
Searching with Subject Headings
Using subject headings to search the library catalog can help you quickly find useful books. Once you have found a book on your research topic, click on the Subjects links to find more books on that topic.
You can also search by subject in an advanced search. Here's a sample of relevant subject headings for architecture research:
ARCHITECTS AND BUILDERS
ARCHITECTURE AND ENERGY CONSERVATION
ARCHITECTURE -- UNITED STATES
Searching by Architect
To find books about architects, search using the architect's name as the subject, for example: