One of the most enjoyable ways to improve your English is by reading!
In the «Learning English» tab, you will find links to some of the most interesting free online libraries available.
The LibriVox Audiobook Collection is a site which belongs to the public domain. The books have been read by volunteers and are for listening. Only for very advanced students.
Find the classics of all times full-length in Project Gutenberg and Planet eBooks.
Fiction eBooks will give you the opportunity to read online not only fiction books but many other genres as well as link you to other libraries.
Finally, English E-Reader is the one I recommend for most students as you can not only choose various genres but also levels ranging from A1 to C2.
“If you don’t like to read, you haven’t found the right book.” – J.K. Rowling