From the lead page of Website
Design & Maintenance:
Many well designed websites use a simple basic white background. Images and other colors can be effective, however, white backgrounds have many advantages. Typically providing improved background image matching, neutral white helps to emphasize content.
Editing images is an important part of web site design; Digital photo editing programs allow opportunities to develop interesting graphics, often using files originally produced by consumer cameras.
File sizes of images effect how much time a web page need to 'load'. Faster is better so best to have smaller file sizes with web standard file formats like Graphics Interchange Format (GIF), Joint Photographic Experts Group (JPEG or JPG) and Portable Network Graphics (PNG). This web page contains many photos, so it might load slower than other web pages.
Digital photo editing programs allow opportunities to develop interesting images. Usually, editing is most effective when original (camera) images are high resolution and lighting is well balanced. Most modern digital cameras are capable of producing high resolution images.
"Before" images shown here resized (smaller);
original images were much larger.
"After"
images with frames
Cropped to remove sections from the top and left side, the image was rotated 2 degrees so the lighthouse would appear vertical.
Color edited to accent red and a little bit of blue.
Cape Hatteras Light,
Cape Hatteras
National Seashore.
Cropped to remove section from the right side, edited to have a small 'Depth of field'.
This technique, 'Depth of field' is very popular as it bring attention to the subject (in this case, the foremost flowers.)
Color edited to accent yellow.
Original photo
taken in low light conditions.
Color edited to accent red.
Georgia Aquarium
Cropped to remove section from the bottom and left side, edited to have a small 'Depth of field'.
Upstate
New York
Removed overhanging tree (near the moon), balanced many colors and lighting
Cropped to center, edited to have a small 'Depth of field'.
Clear "Vector" text added.
Cropped to a very small portion of the original image
(center / right)
Composite image of public domain 'clip art' & line drawing.
Cropped to remove sections from the top and left side, the image was rotated 2 degrees so the lighthouse would appear vertical. 
Cropped to remove section from the right side, edited to have a small 'Depth of field'.
Original photo
taken in low light conditions. 
Cropped to center, edited to have a small 'Depth of field'.
Cropped to a very small portion of the original image 
