Using Books at Google
Perhaps you find a useful, out-of-copyright, book that has been digitized at Google [Google Books] and you have figured out how to download it (in PDF) to your laptop, desktop computer or tablet.
Many of these older books contain amazing information that you would never have found out about an ancestor, a location, city or town histories or subject matter that you need to learn about. It really is amazing what you can find.
After opening the book (in PDF format), you should not miss the notice on the first page that reminds you that to search the contents of a downloaded book, it is best done by searching the book via Google's Web site. What I didn't know is that the link (as shown below) in each book will bring you to Google's Web page so you can search it.
See the box around the URL? Click on it to find the book you downloaded. This way, that book is permanently connected to being able to search the contents. I have downloaded so many that I can't remember why I downloaded it.
I am planning to pin the books at Pinterest so that if I am sharing my latest obsession with another researcher or on my blog, they can click on the pin and open the book. It is working quite well.