Here you can find some good books downloadable for free:

The Adventures of Sherlock Holmes by Sir Arthur Conan Doyle

The Art of War by Sunzi 6th cent. B.C.

The Kama Sutra of Vatsyayana by Vatsyayana

Metamorphosis by Franz Kafka

Dracula by Bram Stoker

The Picture of Dorian Gray by Oscar Wilde

The Iliad by Homer

The Sign of the Four by Sir Arthur Conan Doyle

The Count of Monte Cristo by Alexandre Dumas 

Sex by Henry Stanton

Les Misérables by Victor Hugo

The Bible, Old and New Testaments, King James Version

The Dark House by I. A. R. Wylie

Malcolm Sage, Detective by Herbert George Jenkins