Okay, I just found some random motherboard picture, and circled what they should look like. It'll be one of those tiny sections that I circled in red:
Since you don't have a manual, the order in which you plug them in may not be easy to figure out. I'll see if I can find information on that particular computer's motherboard for you. If not, I'll consult my motherboard's manual and tell you how it tells to do it and see if it works that way.
Edit: I cannot find enough information on your computer's motherboard to help you. I also don't know where my motherboard's manual is. If you have no manual, you may have to get some information from eMachines on how you need to plug in all of that.
Edit #2: Opera sucks. It isn't editing my posts when I edit them. I have to delete the thread and repost everything....