The following are a list of resources to aid you in how to conduct yourself as a professional in the world of professional graphic design. Examples in include how to charge for design, how to draw up an agreement or contract with a client, how to invoice for design. In general in it is always advisable to error on the side of formality when doing business, no matter how small the service or design project may seem. This is especially true when doing work for a family member or friend. You do not want accidental misconceptions or misunderstandings about what is expected to ruin an otherwise great relationship. So, keep everything in writing right from the beginning. Your friend/client will appreciate this and respect you more as a professional… and you will remain friends!
Your best source for best business practices, contractual agreements, copywrite, ethical business guidelines, etc. is Graphic Artist Guild Handbook on Pricing & Ethical Guidelines