When you say problems starting do you mean it turns over a long time before it finally starts or does it turn over slowly sometimes (or not at all)?

Once it does start, does it run good/normal?

It could be a variety of things but if you feel it might be the cables or their connections just make sure they're tight w/ no corrosion on them. You can follow the positive battery cable to where it connects to the starter.

Also check where the negative battery cable grounds to the chassis and the ground running from the transmission to the chassis.

If the cables look very dark (or even black ) it wouldn't be bad to replace them but otherwise I doubt that's it.