First published in 1901 and 1902 in serialized form, this is probably the most well-known of the Holmes novels. Although A Study in Scarlet has its iconic moments involving Watson meeting Holmes, Hound seems to be the go-to Holmes story. For example, when the kids show "Wishbone" did a Holmes story, they selected The Hound of the Baskervilles. It has been adapted into radio plays and movies multiple times.
There are good reasons for the popularity of this novel. Hound has everything a classic Holmes novel should have: fog, a moor, a spooky house, distant family relations, and a vaguely supernatural mystery. There are some very good Holmes stories told in London, but the atmosphere of stories like Hound make for more iconic stories.The fun of this novel is that Holmes and Watson split up, and what we get of the investigation is almost all from Watson's perspective. These parts are told via letters written by Watson to Holmes, and conversations between Watson and various members of the Baskerville household. Of course Holmes shows up in a dramatic way at the end to solve the mystery and set Watson straight.
I find the Sherlock Holmes novels to generally be more satisfying that the short stores, or at least more consistently good. The extra space allows Doyle to build a more complex plot, and explore character relationships. And he does so here, without the long diversion to Utah we get in A Study in Scarlet. The Holmes opus can be daunting, containing as it does four novels and fifty-six short stories. But this novel may be the best place for a newbie to start.