Do yourself a favor. Dont mix business with family or close friends.
Everyone else, charge.
Your friend can do his (federal) taxes for free using popular programs. The IRS website has a link (if the moderators will allow the link you can find it here… http://apps.irs.gov/app/freeFile/jsp/index.jsp?ck
He can do his state taxes for $39 with turbo tax, including efile and direct deposit of his (hopefully) refund.