The connections on the back of the MaKey MaKey are what's called "female header." They're rows of little sockets, designed for wires to stick into. The easiest way to use them is with jumper wires, which are wires with little pins on either end that stick nicely into the header. The Deluxe kits come with packs of jumper wires. You can also buy them separately from sparkfun- be sure to get the male/male ones, like these: http://www.sparkfun.com/products/11026 Jumpers are convenient, but you can also plug regular wire into the header. Solid core wire is best, and you will need wire strippers to remove the insulation from the ends of the wire. You can also find clever ways to use stuff you already have- for example, we've found that both paper clips and safety pins work great for this purpose!