Brasiliana - Digitized multidisciplinary collection of works about Brazil published between 1931 and 1993 by Companhia Editora Nacional.
Brazilian Government Documents - Executive branch serial documents issued by Brazil’s national government between 1821 and 1993, and by its provincial governments from the earliest available for each province to the end of the first Republic in 1930.
Domínio Público - Digitized items (text, sound recordings, video, images) in the public domain.
Tráfico de Escravos no Brasil - Digitized images and texts related to the slave trade in Brazil.
The Luso-Hispanic New World in Early Prints and Photographs - from the New York Public Library.
There are over 5,000 public libraries in Brazil. They belong to the Sistema Nacional de Bibliotecas Públicas, a Sistema Estadual de Bibliotecas Públicas, and/or a Sistema Municipal de Bibliotecas Públicas. Some university, school, and special libraries are also considered public libraries.
There are over 3,000 museums in Brazil. Here are online resources to find one near your destination and to suit your interests:
Guide to Museums in Brazil -- free to download online from the Ministry of Culture and the Brazilian Institute of Museums. Organized by region and with a special section on museums under construction, virtual museums, now-defunct museums, and museum name changes. In Portuguese.