I'm creating an ebook that has images in it. What size / resolution should images in an ebook be?
Here's the deal with Kindle images. The bigger, the better -- up to the max size (in bytes 5Mb) The largest Height x Width possible so users can zoom in. Why do I say this? Because the Kindle Reader now allows the reader to click the image and then zoom in on it.
That means you want the image to have a high resolution so the user can click on the image inline (in the text) and the Kindle Reader will take over and allow the user to zoom in using multitouch features of pads (iPad, iPhone, Android, etc).
So, the better the resolution the better the experience. I know this is true because I've tested it in my own books where I've used graphics and I've also been pleased and annoyed by other author's books I've bought which had good or bad resolutions set and then I couldn't really see their images clearly.