There are free resources available from many places. Remember that our Database page has more research tools as well.
Welcome to Smithsonian Open Access, where you can download, share, and reuse millions of the Smithsonian’s images—right now, without asking. With new platforms and tools, you have easier access to more than 3 million 2D and 3D digital items from our collections—with many more to come. This includes images and data from across the Smithsonian’s 19 museums, nine research centers, libraries, archives, and the National Zoo.
Wikipedia is a good source for general information. If you don’t know something about a topic, a good place to start is on Wikipedia to learn more about it. From here you can use that knowledge to make more specific searches. Remember that anyone can edit information on Wikipedia, so it's best to check multiple resources if you think the information is incorrect.