I'd put money on the probability that most Internet users have had to grab and optimize screenshots for cyber use. While some of us are lucky enough to have professional graphic artists on our side, it's important to know how to quickly create and touch up an image for the Web. For example, you might want to create your own avatar from a real-life photo or digital graphic.
Editing images for the Web is a different process than editing for print, and it therefore calls for its own approach. That's primarily because screen resolution can affect how easily the eye can interpret graphics. Ever noticed that faint flicker on the screen? Eyes have to work harder to overcome that subtle interference and process a clear image.
The "print screen" button standard to most desktops and laptops takes a full-screen capture that copies into Word and text documents. It's OK in a pinch, but the technology is simply outdated. Other programs utilize more-advanced capture and editing features, including SnagIt and Ashampoo Magic Snap. Interestingly, more publishers are integrating proprietary screen-capture software into their applications. The popular virtual world Second Life and GOM Media Player, for example, let users take screenshots without having to stop what they're doing to launch an external app.
Though many screenshot programs contain editing tools, few are as powerful as dedicated image editors. Adobe Photoshop Elements has excellent tools for touching up and resizing photos within your chosen ratio. The free, much more focused Paint.NET is also great at preserving image ratio, though weak red-eye tools make it less than ideal for publishing portraits.
Whichever of the many image editors you choose for importing the graphic, the important thing is to save it in the right format and with the right quality. Adobe products differentiate with a "save to Web" mode, which presents a window for previewing the image when it's published.
As users' Internet connection speed varies, images are best saved at medium or medium-high quality. They should appear smooth in the preview window, not grainy. The JPG format is really ideal for photos, whereas images with limited colors present better as GIFs.