installing a pre set/hung interior door..

This door will lead into a toilet room, I am not sure when to install. Should i install before or after i set the floor stone? My assumption is after so I can gauge where to mount the door vertically off the finished floor.
I havent hung a door since I was working summers for my uncle when i was 17. So several years later I need a refreshing on how ot do it right, seems simple enough but I want to do it once.

Should I start my plumbing the jamb on the hinge side and temp set with finish nails then plumb the jamb on the opening side? Any suggestions?

thanks
Chris

Install it after you get your finished floor in place. That way, you can get the tile, wood, etc. under the trim and make it look nice. Trying to cut tile to the door trim, then caulking it is messy, and it looks nicer if the trim goes down and sits tight to the top of the floor. If the hinge side stud is nice and straight and plumb, you could attach that side to that and shim the other. Often, you need to shim both sides. I like to subsitute one longer screw in each hinge and go into the stud with it. On a prehung door, the screws are fairly short.

Thanks Jim,
the idea of longer screw in each hinge plate will be good idea. The door is not hollow and has frosted glass panes too.

Chris