4 pin fan

very stupid question, but ive got to ask it. my fans have a 4 pin connector as well as a molex connector that splits out. do i just connect the 4 pin connector with a molex connector from my psu? also, does the molex connector on the fan have only certain uses or can it power any peripheral that has a molex connector port

Molex goes to molex and it's to power the fan. If you ran has additional connectors that don't look like molex, it's for powering fan (2 rails), rpm readout and speed adjustment.

it has a connector which a psu's molex connector should probably fit into to power the fan. theres also a connector from the fan that is identical to a molex connector. what you are saying is that this molex connector thats coming out of the fan should only be used to power an rpm controller and not anything else, such as my video card (which has a molex connector port)?

As long as all 4 wires are present, it can go to anything. Just remember that every time there is a connection a little bot of voltage is dropped. Probably not much to worry about, but I usually just put fans off of fans.

Basicaly the wires go yellow, black, black, red

yeah its generally a good idea to keep power to components like video gards and hard drives separate from fans