Amazon announced a new Book subscription service named Kindle Unlimited. This service is currently available only for the United States customers only. Amazon says they will expand this to more countries soon.
This service have more than 600,000 books and also audio books. You can try the service for free for 30 days. The service is $9.99 per month. You can keep up to 10 books at a time while they will not have any due dates. So you can read them when ever you want and you can take your time to read. But if you cancel your membership all the titles you selected will be removed from your account and devices. To add a new title you will have to return one (if you have reached the limit of 10)
Features
More than 600,000 books
Includes Best sellers like Lord of the Rings trilogy, the Harry Potter series, Diary of a Wimpy Kid books etc.
More than 2000 Audio books
Books available exclusively on Kindle
Free three-month Audible membership
You can download the Kindle application on your Android, iOS, or windows device to get this service.
You will need an Amazon account, credit card to use this service.
You can read more here - https://www.amazon.com/kindleunlimited