How to perform cleanup duties on OS X?
Alex.. please be careful.  OS X generally doesn't need maintenance like most Windows installations do.  If you just leave it, it will be fine.  The only thing I sometimes tell clients who I'm tutoring, is that the maintenance scripts run themselves by default at 3AM.  They're not doing anything too serious, log rotations and the like.  So if they don't run, I don't think it's the end of the world.  But once in a while you may want to leave the computer on all night so they get done.