As the name implies, Google Books is a search engine for locating books. Through Google Books you’ll find books that you can read in their entirety for free and books that you can preview for free. Most importantly, Google Books lets you search for keywords within books. Searches on Google Books can be refined according to date of publication, access level (full view vs. preview-only), and publication type (book vs. periodical).
A typical example of using Google Books in a history setting is found in a search for information about the Battle of New Orleans in The War of 1812. Head to Google Books and enter a search for “War of 1812.” Then refine the search to books with a full view published in the 20th Century and you’ll quickly locate The Naval War of 1812, volume 2 authored by Theodore Roosevelt in 1906. You can then use the “search inside” function to find every page that makes a reference to New Orleans. You can then quickly jump to each page that references New Orleans because each page in the search result is hyperlinked. You can read those pages online or print them for reading offline.
It should also be noted that you can search within books that are marked as preview-only. The utility in that is identifying how much content there is related to your search term within a chosen book. If that search reveals that there is a substantial amount of useful content, you can then use the “get the book” function in Google Books to locate libraries in your area that have a copy of the book. The “get the book” function will also provide links to places to purchase copies.
A video overview of how to use Google Books is available here and is embedded below.