1. Start by formatting an image for web use using photoshop or another image editor, The image should have its width be 1000 pixels, 72 dpi and saved with an image quality of 75%.
If you are not familiar with photoshop there is an online image editor you can use at http://jpeg-optimizer.com.
2. Open up http://jpeg-optimizer.com and choose the file from your hard drive you want to optimize. Use the settings above…
3. When you click “Optimize Photo” it will show you your optimized image – click on the image and save it to the location of your choice – a suggestion would be a common folder on the desktop.