This past year I discovered the wonderful world of receiving ebooks directly from authors (or their publisher) for free in return for reading and then writing a review and posting it on Amazon and Goodreads. One of the connections that I use quite often is called BookRooster. With BookRooster, you sign up and indicate your preferred genres to read and then when they have a book available that you might be interested in, they'll email you with a short blurb about the book and an invitation to review it. Then it 's up to you to decide if you'd like to read and review it or pass on it. There's no minimum amount of books that you need to commit to and you only read the books that you accept the invitation to. Just be sure to respond to the invitation quickly because they only have a certain number of books to send out and if you wait, they may have already sent out all available reviewing copies!
You can sign up as a reviewer or as an author who is interested in having your book put out for review. Simply go to BookRooster.com and click on the appropriate tab and sign up!!