Google has just officially launched its new eTextbook rental and purchasing service in the US. This feature does not currently have its own section, instead it is an integrated part of Google Books.
The new digital textbook section has offerings from most major publishers such as Pearson, Wiley, Macmillian Higher Education, McGraw-Hill and Cengage Learning. The current textbooks only offer the ability to buy or rent, with only a handful allowing you to do both. Each edition as a free sample that typically covers a few chapters to offer a sense of how the books look. A purchased digital edition is automatically delivered to the reader via the Google Books app. If the official e-reading app is not preferred, there is an internet browser alternative and some titles even allow exporting to a reader such as Nook or Kobo.