If you have read the story, hopefully you know what the outcome of it is; if you haven't read it, I recommend it. It's one of Poe's most engaging and interesting stories, and it isn't very long. The ending is awesome; I provided a link to the story below. To sum up, the cops come by asking questions about the old guy that disappeared, and the narrator, so cocky about his cleverness in the murder, sits them all down right on top of the floorboards that old man is buried under. Then, the narrator starts thinking that he hears the old man's heart beating. It gets louder and louder and the narrator assumes the cops must hear it too, and after a few minutes, in a fit of desperacy, he confesses his murder.
The lessons or morals that we can take away from this story are several. 1. Guilt is our worst tormentor, and will always drive us to do what is right. The narrator thought he was above guilt, but it manifested itself in the form of the beating heart, and drives him to confession in the end. 2. Pride goes before the fall; the narrator was so cocky and proud that he brings the cops right to the scene of the crime. Poe doesn't let his pride win though; in the end, he confesses. 3. This is rather trite, but don't murder people. So, those are a few lessons that one can take away from this story. I hope that those thoughts help; good luck!