|Take alook at this page...|
Third post should show a pic of your motherboard. Does yours have the long black slot above the two short white slots?
If the original power supply is present, it should be a Bestec 300W; a very shaky unit, barely able to power the basic computer, prone to failure...you get the idea.
What do you want to do with this? Imagine play some games? If so, what games?
Not that I'm trying to talk you out of this project but hell, that's precisely what I'm trying to do.
You don't have a very good beginning platform to do much of anything and shouldn't consider spending much money as you can quickly spend more than the machine is worth.