Just a quick tip about loading your large JPEG files to your website either after you’ve taken them from a good digital camera or downloading them from a stock photography website. Many of the images will be 300dpi (dots per inch) which means that they are prepared for print and not for your website. In order to get them into web ready images, the resolution must be set at 72dpi. You can re-size your photos by opening them in a program such as Adobe Photoshop and setting the resolution to 72dpi. Sometimes the dpi is set to 72 but the size is still very large. One thing that I do is to check the dimensions. Even though the resolution could be correct, the dimensions could still be very large.
After setting the correct size, save your photo in GIF format and not JPEG format. This insures that you have an image that will not slow your page load time when your visitors browse your website. There are settings within the GIF save-as mode that you can tweak to produce the best looking image.
An example of a large photo is one with 72dpi and dimensions of 3280×2300(in pixels).
An example of a web ready photo is one with 72dpi and dimensions of 550×320.