on most tables it doesn't matter but on some it does, best to keep them in the same locations and any decent table will have a nameplate which belongs at the head of the table where you break from..
Maybe I'm misinterpreting the question, but in my opinion, if you don't know the difference between a side rail and end rail, you shouldn't be worried about where the fold goes. You should probably get in touch with someone who does it for a living. What area are you in, you might get someone on here that could help you out.