will give you the installation directory of mplayer. I suggest you look at rpm command.
also try to google for man rpm keyword. Also here are few links you might want to check out to get around linux.
- excellent source for guides to getting around in linux.
- Linux newbie administrator guide...very useful for newbie.
get a decent book for linux for a handy reference. Check out the book reviews section of LQ.
Hope this helps!