Photo galleries are sets of full-screen, cross-fading photographs
Prepare your photos
Prepare photos for a web gallery by cropping them to 900x600 pixels. Vertical shots should be 600px tall - the width is flexible ("empty" space on either side of the photo will be matted with black).
When saving these photos, you should aim for a file sizes below 120KB. Adobe Photoshop's "Save for Web" function is an excellent tool for lowering file size while maintaining image quality.