They will work either way you place them depending on your preferance.
Don't bother taking a yard stick out and measuring your room... They don't care and really don't have a clue.
In the manual there will be a section on setting it up. They are going to lead you through several areas... where the speakers are located in respect to where you sit. How high off the ground they are etc etc.
Good rule of thumb, is to keep the right and left front speakers about 3 feet to either side of the TV, and the backs should be the in the same spot across the room, at ear level.
When they ask how far the front speakers are from you, they are setting up the surround, so you hear it properly. so make sure you get that as close to on the nut as you can.
I didn't get a real good look, however they all seemed to be the same speaker with possibly the exception of the center. Which should be placed on top of the TV by the way, so you shouldn't have to worry about which speaker goes where, they are all the same, regardless of what the little speaker on the back says.
If you are able to use your own speaker wire, which I presume you won't with this package, I recommend getting better wire than comes with the package. It's going to sound and work a lot better that way.