go to the event editor and double click on a space. Now, in rm2k/2k3 there is a button that says SET near a little box. click on it and pick the sprite that you want the NPC to look like. in XP it is just an empty box. In the events you can make it move around or talk or whatever. for talking, on the left side under trigger condition select "action key". then on the right make a message event and have it say whatever you want.