Little Beach is right next to Big Beach. Note that Big Beach is in Makena State Park - the original name is Oneloa Beach. It is actually beyond Wailea, in Makena.

After you park, when you get to the beach, while facing the ocean, walk to the right. There's a small cindar cone which you will walk up and over, then down to the "little" beach. There are no bathroom facilities nor lifeguards. This is one of two "clothing optional" beaches on Maui. Sometimes there's nude surfing, as the summer brings waves this way. There is quite a current just off shore, so be aware of how the ocean moves.  

Spend the day on Big Beach (it is BIG & awesome) & then spend the evening on Little Beach. Sunday evening, beginning at 6p.m., is the time to be there. Every Sunday evening, a drum circle (very cool & very hippie) goes on. If you are pretty conservative & have young kids, do not attend the drum circle. There is nudity.