1. Optimizing Images for the Web
Using Photoshop

2. Open File to Work With

3. Modify..Canvas..Image Size…

4. Select Desired Dimensions

5. File…Save for Web and Devices…

6. Switch to 4-Up view to compare 4 variations

7. Zoom out so can see image

8. Configure Previews
Clicking on a preview pane lets you change settings for that preview
You can optimize by removing colors, increasing compression, etc.
See which still looks acceptable
When finished, click the pane you want to export
Click the Save button

9. Select where you want to save the file

10. Compare Original to Optimized
Wow!