I also try to keep track of which rotation a team is in. If a team is in rotation 1, for example, the setter is RB. The libero will (usually -- see Felix's comment) be CB. The setter's opposite will be LF, the middle will be CF. That only leaves two players "unaccounted for" -- and I'm working on that.
Also, Scrapper posted a good video from his association on rotations and where the players are . Search for it on here (it's been a couple of years, so it won't show up in the list of threads without searching for it).