This site can help you.
RE:
From .PSD to vector (.ai or .eps)?
I designed a logo for someone else in Photoshop and now he wants it in vector format (.ai or .eps) but I don’t know how to convert it. I have Photoshop and Illustrator CS3. I tried opening the Photoshop .png file in Illustrator and live tracing it, but the results are not good…