The original Sherlock Holmes stories by Arthur Conan Doyle consist of four novels and 56 short stories, published between 1887 and 1927.
The novels are:
- A Study in Scarlet
- The Sign of the Four
- The Hound of the Baskervilles
- The Valley of Fear
The short stories are collected in five volumes:
- The Adventures of Sherlock Holmes
- The Memoirs of Sherlock Holmes
- The Return of Sherlock Holmes
- His Last Bow
- The Case-Book of Sherlock Holmes
A Study in Scarlet is the book in which Dr Watson first meets Sherlock Holmes, and therefore perhaps the best book to start with. If you prefer short stories, you could start with The Adventures of Sherlock Holmes.