What Apple PC do you have? Some of them used graphics cards with ADC(apple display connector), it was used to pass power and video signal to the monitor on a single cable, it looks like a DVI connector with rounded sides and you can use a simple adapter to convert it to DVI for a standard monitor.
You can use a standard keyboard and mouse with a mac if its got USB ports, it works normally but you may want to switch around the command and control functionality if you use a standard keyboard.