You won't go all the way with just PC fans but I think most will agree PC fans are great for seedling stage.

You will need a 12 volt adapter or whatever the fans rated for. Ask Radio Shack peeps.

Then, snip the small roundish socket off your adapter.

And with or without a switch in line, go get your fan out.

Should be a small plug going into motherboard. Just unplug it and snip it off. Or leave an inch or so of wire with the plug if you can think of anyone who can use it.

And use those plastic screw on things. You don't need sparking wires inside some electrical tape after the moving fan spins off the end of your finger and dangles around and blows that joint into the wastebasket and the fire department comes in and the leftienant calls in and says the police better bring the K9 sniffer mutt and your wife kicks you out so you end up on skid row and all you can afford is cheap wine once a day. Well. It could happen.