The Case-Book of Sherlock Holmes is a little bit special - there simply aren't enough original Sherlock Holmes stories to satisfy a dedicated reader's appetite, and this volume collects the final twelve stories of the Holmes canon.
First published in The Strand magazine between October 1921 and April 1927, the stories are set way after Holmes' apparent death at the Reichenbach Falls after a struggle with Professor Moriarty. In fact, Holmes is getting old, as Conan Doyle himself was at that time in his life, and some of the stories are even narrated by Holmes itself, and one of them takes place after the great detective's retirement.
Despite all this, and despite being a formidable read in its own right, the Case-Book of Sherlock Holmes is hardly Sir Arthur's greatest work, and while it's a fulfilling read for a Sherlock Holmes fan, it's not as good as some of the early work which made me fall in love with the detective in the first place. But then, any Sherlock Holmes story is a Sherlock Holmes story, and I'm willing to take anything I can get - even, and I dread to think of it, the stuff that was written after Conan Doyle's death by third parties.
There are better places to start if you're new to Sherlock Holmes, but you'd be a fool to miss it either way - it's my firm belief that everyone should read the entire Holmes collection before they die, but each to their own. Keep your eyes peeled for the sinister Adventure of the Sussex Vampire and the book's opening story, The Adventure of the Illustrious Client, both of which are of a superior quality to the rest of the book's contents, ranking up there among the best of Conan Doyle. Not bad at all.