Find an online book site like Goodreads.com. Fill out any necessary information to join the site and go to the “Swap” page.
Choose a book you want and find someone who wants trade it.
Pay the shipping and receive the free book in the mail. (The book is free, but since these types of books come from other people just like you, you do need to pay the shipping costs.)
Find publishers that are looking for people to read and review their books, which will require a little research on your part since not all publishers are looking for reviewers all the time.
Write a cover letter to send to the publishers asking to be a book reviewer. Remember, this is not the same as a reader, who is someone who reads manuscripts before publication and book reviewers read already published books and promote them. Tell the publishers that you enjoy reading and give any other information that may be helpful, such as your education and any book reviews you may have done.
Contact the book publishers either by mail or email. Wait for them to contact you by sending you free books in the mail.
Look for magazines that publish book reviews. Look through different magazines for book reviews.
Follow this example from Christian Library Journal: Log into the magazine's website (see the link below) and read through all the instructions for becoming a reviewer. Fill out the form completely. (Christian Library Journal does not require that you be a professional writer to write reviews.)
Wait for a reply from the editor and start receiving books in the mail directly from the publisher, sometimes in the form of a galley or an ARC (advance reading copy).
Follow all the magazine's instructions for reading the books and writing the reviews; for example, Christian Library Journal has a list of books on the site that you get to choose from. Remember that if you continue to write the short reviews and are in good standing with the magazine, you will continue to receive free books in the mail.