Making money with covers and sampling

[Palpatine]

I was wondering when a band/singer covers a song how much do they get and how much do the original writers get? E.g. covers that were huge hits, like Tainted Love and Always on my mind, who gets what? Also, how does it work if an original song has a sample(s)? A song like Theme from S'Express has over a dozen samples and is a big hit, who gets what?