Move Furniture Around:
Click on It. Move it with the mouse.
Use '+' and '-' to go up or down a floor.
Use '7' and '9' to rotate the furniture.
Basically on a full sized keyboard anything East of the Backslash is game.
Move House Around:
Use '4' and '6' to move left and right(X).
Use '1' and '3' to move up and down(Y).
Use '2' and '8' to move forwards and backwards(Z).
Up and Down arrow are for the X axis.
Left and Right arrow are for the Y axis.
Home/End/Page Up/Page Down are for the Z axis.