I use one main image that is a full size page (11.25" wide by 8.625" tall including a bleed) and I use 2-3 detail shots on the other page. The easiest way to explain it– for those unfamiliar with all the technical jargon– would be the actual camera raw photo files. Not the ones uploaded to the internet and then pulled off. This varies greatly depending on camera settings, export settings etc. I get the actual camera photos, 9 out of 10 times they work just fine. I can resize them DOWN and crop very easily. Scaling them UP is a problem and creates pixelation and fuzziness. Travis is correct in that if they are 8MB and up (not KB) they should work fine.