Claudia - I am from the US and live in Peru now. I had to do the same thing for my teaching job. You have to get your University in which you received the degree to send a certified copy of your diploma to the Secretary of State office. I received my degrees in Missouri... so I asked my Univ to send my degree to the S of S in Missouri to get an Apostille Stamp... basically like a notary stamp saying its a valid degree.
Once you get the Apostille stamp you must send that to a Peruvian consulate in the US... for me, since I was in Missouri, the closest consulate is in Chicago. Once you send it to the Peruvian consulate they will notarize it and verify that it is legal.
Each process has a fee, so I suggest calling your University, your state's Secretary of State office, and the local Peru consulate to organize how you're going to pay for the fees.