soldering iron: For a start. Nothing fancy; a 20 or 25 watt sub-$AU20 cheapo-iron will do pcb board led, as long as it's got a fine tip. Giant plumbing irons, soldering guns or metalworking irons that you heat up in a flame are not what you want. You'll also need something vaguely resembling an ability to solder. If you've never soldered before, pcb board led it's not hard to learn. There are lots of how-to-solder guides available online.
Computer power connectors pcb board led separately and wire 'em up : You could put a drive power receptacle on the side of your caselight's enclosure, or just hard-splice its supply wires into a PSU lead. But this is a straightforward solution, particularly when you consider that bare computer plugs and sockets can be a bit tricky to find.
An appropriately rated resistor: Suit whatever array you intend to make. Resistors are very cheap and available in a wide range of power ratings and values.
PSU-to-three-pin adapter: Which comes with various CPU coolers to allow people to run the pcb board led CPU cooler fan in computers with no three pin headers on the motherboard. There are only two wires going to the fan connector, but they're all you need; they're +12V and ground. The third wire in a three-wire lead is the fan tachometer connection pcb board led.
"veroboard":This is ordinary single-sided pcb board led circuit board with a pre-applied multi-purpose copper pattern on it. It makes it quite easy to create simple circuits, like an pcb board led LED array. It probably isn't made by Vero Electronics any more, but "veroboard" is a trade name that's stuck. It sounds better than "perforated stripboard prototyping pcb board led medium"