Google Books for Android offers an awesome way to sync your books across multiple devices, and even your computer. What can be easily overlooked is the fact that most of your reading material is only available while you're online. So if you want to read while you're traveling (or just looking to save some battery by turning off your data connection) it's a good idea to make sure the next books on your reading list are downloaded to your tablet. Here's how:
Step 1: Open the Google Books app and find a title you'd like to read while offline.
Step 2: Press and hold on the book's cover and a new menu will pop up.
Step 3: Choose make available offline.
Step 4: Select other titles you want available in offline mode by pressing the small thumbtack under each book's cover.
Step 5: Once finished, press the Done button in the lower right corner.
You can see how much space you have available for downloads during the book selection (shown above). And it's OK to pick all titles, as long as you have the space.