Books are wonderful, in depth sources for biographical material. They go into much more detail than background resources and web sites, and are usually more academic.
When searching for biographical material in our catalog, try doing a "subject" search and combining your person's name with the term "biography":
Example: Barack Obama biography
Please note that autobiographies and memoirs are also indexed as "biography."
Some other terms that may be helpful, and are related to biography are: diaries; correspondence (letters); and speeches.
Examples: