Hello and welcome to Tom's Hardware Forums.
Probably something quite simple and not to be downhearted about. How far does it go? Did you get an operating system into it yet and, if so, does it just die at boottime or have you not got it to stay on at all yet?
Are there any beeps coming from the system speaker and if so, what configuration of beep? Try removing one of the RAM sticks - assuming you have more than one. If that makes no difference, put it back and remove the other one.