The piston will have a marking on the crown that faces the front(crank pulley) hope you marked witch piston came out of witch pot, put them back in the same pot.
Rings are usually marked "TOP" you fit them facing the top(crown) of the piston. If for some reason they are not marked look at the shape of the rings the top ring or no1 ring is a perfect square ring(that does sound weird)and can be fitted anyway round, the second ring from the top will have a recessed edge and that ring if not marked is fitted with the recess facing the bottom of the piston or sump, the oil ring depends on the type of rings you bought, if a two pice oil ring it is also marked with "TOP" fit the spring first before you fit the oil ring, if a three pice ring you will have a spring/expansion and two very thin steel rings, these steel rings you must take and hold between your thumb and index finger with the ring gap facing away from your palm, and squeeze gently on the ring trying to well you will close the ring gap but keep an eye on in witch direction the ring collapses, is it away from you or towards you and remember that and fit the ring on the piston so that the way it collapsed in your hand collapses towards the bottom of the piston.
I hope this made sense.
Sorry and the installation is the wrong way round from my description, you start with the oil ring and work your way up.