You do have a power supply, right? About switching it on, find on the mobo where you would plug in a power switch (should say "pwr swtch", "soft pwr" etc). There are two "terminals" for that plug. Touch a flathead screw-driver to those terminals, and the computer should come on. I really suggest getting a case because if you have static electricity built up in your body and you touch the mobo in the wrong spot, your mobo is fried!