Which edition do you use? Does it have notes?
It's definitely mostly accessible but there are some outdated language or concepts that would probably be helped to be explained. I know you already got yours but for those looking at buying, try get one with footnotes, don't try save a few bucks, it'll make it so much better.
I use the Penguin Classics edition, it has a really in-depth section in the back to explain certain concepts in the book, as well as broader English society during Doyle's time. I got it off bookdepository for about $8.
I read The Hound of the Baskervilles, and it's so damn good. Not too many books really get me caught up in the suspense, but Doyle's atmospheric descriptions, which kind of have a hint of totality to them, really draw you into the story.
Has anyone here read any Edgar Allan Poe? On a whim last week, I read 'The Fall of the House of Usher' and 'Murders in the Rue Morgue', and they were magnificent in their storytelling, especially the former. Highly, highly recommended.