I have authored a technical book and done formatting and editing for about 10 nontechnical ebooks. I know the epub3 and kindle standard very well (but not multimedia). I'm not really a graphics person, but I have tackled some difficult formatting issues related to book art. No editor is perfect, but I have excellent quality control procedures. I can be hired to do a single service (proofing, formatting, etc) or a combination of services (proofing + formatting or editing + proofing + formatting). I don't give lowball bids; I know how much time it takes to produce quality work!