Very cool,
The native people in Peru are located in the coast, Mountaint (Andes) or the rainforest. The rainforest natives would be the most different experience and the andean natives would be the most cultural. You can either contact a NGO or universtity for a community project where you go and help, or you can just grab your backpack. The easiest and safest way would be the NGO, just going yourself it quite difficult as most natives are on the defensive and are not too open to foreigners living in their communities.
I reccomend joining a NGO, or similar group. Hope thi shelps..
Richard Leon
www.peruforless.com