Lit 2 Go: a free online collection of books, stories and poems in Mp3 (audiobook) format. Each reading passage can also be downloaded as a PDF. Suitable for B1- C2 level students.
Short Story Project: an extensive collection of handpicked short stories from around the world. Recommended for more accomplished and ambitious readers (B2-C2).
The English e-Reader Website: download e-books and their mp3 audio files. There are books for all levels, from A1 (starter) to C2 (unabridged).
American Literature: you can find here copyright free short stories and classic literature
Linguapress: large collection of graded English texts with activities (B1-B2).
Extensive Reading Central: reading and listening practice for learners of English as a foreign language at different levels.
British Council: here you can find activities to practise your reading skills with different types of texts and interactive exercises (A1-C1)