I believe you stand in front of the door with the door swinging opposite you. What side is the knob on? So stand outside your bedroom (assuming bedroom door swings in, it should) and see where the knob is.

(This is coming from a guy who has come home from the local store with the wrong door!!)

I just replaced all the mahogany flush doors in my house with oak. I got 6 right and 1 wrong. After getting the one wrong, I pictured each door in my head then went to the local store and stood in front of each door.

Looking from the outside (be it outside the house or outside of the room) the handing of the door is which side the hinges will be on (ex. hinges on right, you have a right hand door)!!