The Hound of the Baskervilles (text) is dead famous. You've certainly heard of it even if you haven't read it. As a book, it is fun to read. As a crime story, it is badly lacking.
The decent bits: well, it's a Sherlock Holmes story, fairly well written, and all that kind of thing. I won't bore you with the details.
Wiki says "It incorporates five plots: the ostensible 'curse' story; the two red-herring sub-plots concerning Selden and the other stranger living on the moor; the actual events occurring to Baskerville as narrated by Watson; and the hidden plot to be discovered by Holmes. Doyle wrote that the novel was originally conceived as a straight 'Victorian creeper' (as seen in the works of J. Sheridan Le Fanu), with the idea of introducing Holmes as the deus ex machina only arising later." And perhaps that explains some things.
The lack: by the end, Holmes seems to have needed an extraordinary number of clues to get the answer. And seems to find a rather odd balance between saving Sir Henry and catching the murderer. Plot holes: this is a lonely part of Devon, and yet both Holmes and Cartwright come and go freely without anyone noticing. Cartwright, in particular, is a young lad bringing Holmes food out onto the moor - at a time when there is an escaped convict, Selden, out there who needs food - and yet no-one suspects anything. One of the characters has even seen him, but does nothing. Where is Cartwright living? The convict dies on the moor - and yet there is no fuss. No explanations to police or coroner are required. the idea that Stapleton could conceal and control an enormous dog seems implausible; as does the idea of it standing for being painted with phosphorous. And so on.