You can use some Woodbury Library databases research companies like studios and publishers. These databases often have information about the people working at a company, the company's financial information, a listing of their competitors, links to recent news articles about the company, and more. Below are a few databases to try.
As you probably realize, there will not be entire books about most animation studios, but we do have a few books on our shelves you may find helpful in researching animation studios and their history and culture.
Animating Your Career by 
Directing for Animation by 