You will not be able to fully access all books on Google Books. The different viewing levels are:
Search the world's most comprehensive index of full-text books. Google is scanning the entire collection of some of the world's greatest libraries: Harvard, Oxford, Stanford, University of Michigan, New York Public Library and more. Google has millions of books online already. Magazines and newspapers are also available. Go to Google Books now.
Google Books have different levels of accessibility: no preview available, snippet, limited or full view. The views for each book are based on the copyright and copyright owner of each book. If out of copyright, full view. If publisher agrees, limited view. Basic information about the book only, no preview available. The best results tend to be historical, so this feature is best used for subjects like literature and history. Public domain books can even be downloaded in EPUB and PDF format.
Google Books provides many opportunities. You can:
Try an advanced search to limit your results. Different ways to limit your search include author, title, subject, and date.