some questions need to be answered if you want help...
1) what appliances need to be controlled?
2) what provisions already exist on the appliances for remote control, and what are the existing control methods (hard switches, cpu control board, etc...)?
3)what are you proposing as a controller medium (RF, infrared, signals through the power line, wired connection etc...)?
4) what do you want to use as a controller (computer, handheld remote, phone/tablet)?