best places for registers

I am new to doing this but I have been reading an awful lot since I got my new furnance. I have gotten some good ideas from the site. Now on to my question.

I have installed duct work for my add on furnance(Norseman 2500) and was wondering what is the best place for me to put the registers in the rooms. I say to put them in the ceiling(I have drop ceilings), my wife says to put them in the floor(in the corners so not to trip over and stub toes). Just want to know what everyones opinion is.

thanks
pa-mike

The very best place for HEAT resisters is to put them on the outside walls of each room, then in each room put a return air duct on the inside wall as far away from the heat register as possible. Heat rises so put them on the floor. Registers near a stairway will send heat upstairs. I have floor registers in my house and we don't stub out toes on them, they are recessed so that they fit flush with the floorboards. Just be careful you'll get a dog/cat/kid/wet mittens covering every duct before too long.