OK guys, let's not make this sound hard. If you've a Windows based system, it's real simple, and you don't have to download anything, and if it's an Apple system, well, it's even simpler (and if you have an Apple you wouldn't even bother to ask this kind of question). So, let's assume you've the standard Windows system with XP as an operating system, just double (left) click on the photo file, and it'll either come up in some system you've purchased extra software for or came with your camera, or it'll come up in Windows picture and fax viewer. If not the latter, and you don't know how to work with your other photo manipulating system, just right (single) click on the photo file, select the "copy" option, and paste it on your desktop (that's your basic screen after your computer boots up). Now double (left) click on the photo file on your desktop, and if you haven't purchased anything that highjacks the jpeg and similar files, it'll come up in Windows picture and fax viewer, or in Windows picture manager. If in picture manager, you're about home. Just look on the right hand side of the screen for options, and the last one listed is "compress" (no kidding, you're almost done). So double (left) click on "compress" and you'll see your picture and a menu of "don't compress", "documents", "web pages" and "e-mail messages". Each one yields progressively more compression (when you select the circle in front of each option it tells you what size the file will be compressed to - it's a no brainer). Easy. No extra software, or cost. Now, if when you double (left) click on the photo file it comes up in Windows picture and fax viewer, then look at the options bar at the bottom of the screen, and select the option just to the left of the question mark symbol - put's you in Windows photo manager.
Yup, I favor the howitzer approach with Photoshop 7, but you REALLY don't need that complicated, expensive program for posting on the Tractorbynet site - all you need is already on your computer's operating system (yup, Windows Paint works well, but it's a few more steps).