Prezada Gabriela,
It would depend on your preferences. If you could hint what type of book would you like to read, it would be better to give you some hints.
I read the Lord of the Rings and the first book of Harry Potter.
Books by Hemingway. (The Old Man and the Sea, for example).
Audiobooks are also a good option together with the book. You could find some free audios and books in librivox and wikisources.
Best regards,
Antonio