How do I tell which one I have? Is there maybe a diagram or something that can show me the differences? Thanks alot to all in advance.
Look at the pins. If the colors are the same on both ends then it's straight through. If not, it's a crossover.
hold the ends of the connectors above each other in the same orientation. if the colored wires are reversed then its a cross-over cable.
Check out this diagram (on the web link below). It explains in pretty decent detail the difference between straight-through and crossover, and should help.