It's almost always the size of the photo that messes that up. jpgs are limited to 1500 pixels on the longest side or 976kB in size. Almost any camera/phone picture these days will be bigger. If you haven't got a photo editor that can change the image size, it may be easier to host them on another site e.g. Photobucket, and then do a web link to the pictures. Again, if there are display size options, limit the maximum width to 1500 pixels.