SLIDESHOWS...A Correction.

When saving your photos, save them within Photoshop under 'Save for the Web' as a jpg. Within that function, you can size the photo to get a good idea of what it will look like.

When sizing photos for slideshows, the dimensions of the photos are to be 600x400 megapixels. If you use a vertical photo, you need to size it to a height of 400 pixels.