The book that started the adventures of Sherlock Holmes and Dr Watson was A Study in Scarlet. The book is split into two separate but linked stories; Being a Reprint from the Reminiscences of John Watson, M.D., Late of the Army Medical Department & The Country of the Saints. The first part tells the story of Dr. Watson and Sherlock Holmes meeting and their first case. The Second is the background to the case and the reasons why it lead to murder. A Study in Scarlet was a very easy and enjoyable book to read and Sir Arthur Conan Doyle has a beautiful way of writing.