Hi Eric;
As the others have said there are two methods of rigging material, the elastic/EZ line route or the fishing line route, personally I prefer the fishing line with eyelet method, simply because if you take the real aircraft, rigging when tightened, applied extra strength to the aircraft, on the model, when you tighten fishing line it does to a certain extent apply extra strength, but with elastic you can't tighten it up, it always has stretch in it, so you tend to lose that extra strength.
Which ever method you choose don't be frightened of rigging, it can be a bit daunting to start off, but when once you get in to a rhythm it gets easier until you get to a point where you look back and think 'what on earth was I worried about'.
To get to your original question about interior rigging, which ever method you use, doesn't really matter, because it is only for appearance sake that you use it, it's not essential to the strength of the model.
Good luck with your builds and rigging, any problems just ask, you will get nothing but helpful advice and tips on the forum and remember it's only a hobby, enjoy.
Cheers
Pete.