Can someone tell me what is required, as far as suport from someone in the US, for someone that has been selected for the visa lottery? Do they need an affidavit of support? I am a US Citizen and have a friend in Peu that is asking for my help. I just need to know what I am getting into. Thanks in advance for your replies

Diversity Visa applicants use the I-134 so the requirements are the same as what (most) K1 petitioners are required to provide with the same obligations. If he has been selected for the visa lottery, the embassy will provide him with the affidavit of support requirements which he should be able to pass on to you.