Knowing that I have a perplexing question that I just can’t get answered anywhere else, I decided to come straight here to the SDMB. Here’s my situation:
Widely known “rapper” Puff Diddy (whatever) has done a lot of songs which sample heavily from very well-known '80s songs. I am trying to find out the sample used in the Geto Boys song, “Mind Playing Tricks On Me.” Is there a site online somewhere that would have this information? Thanks for all assistance. 
If the wonderfully comprehensive All Music Guide doesn’t have this info, and it doesn’t, then it’s unlikely you’ll find one site which lists tracks and samples. However, you can usually hunt this kind of info down on a track-by-track basis. Look inside the CD - there are usually credits which acknowledge which samples have been taken from which other songs and artists. Or find a user group or bulletin board devoted either to the band or the genre, and ask around.
Incidentally, you may find the Top Samples List provides interesting reading.
They have to go back to baroque music if the list is going to be comprehensive.