Image resizing is an important part of the on-line world. At times we need high resolution images for documentation or printing requirements. However, the bulk of the time our 10 mega-pixel cameras just make life difficult. After what you believe no one wants a 3200×2800 30meg images of your newborn baby bloating their mailbox or message board. The program Picasa is a good entry level free photo editing tool. You can obtain Picasa in the "Google Pack", and install it by itself without the other programs. A link can be found at the top of this page.
Start by opening Picasa and choosing a directory on your hard drive to work from. If this is your first time running Picasa it may want to scan you drive for photos. Due to the time associated with this I suggest only letting it scan you desktop. For this write up I navigated to my desktop.
Once you have selected the directory you want to work with, you will be provided with thumbnail images of every file in that directory. Select the image you want to resize by clicking on it once. Then click "export" located at the bottom right of the screen.
Click the export button. The next entry you need to make is where to put the images. This is done by changing the targeted directory in the blue box. I usually work off the desktop as it makes locating the images I have resized easy to locate. Images you export in Picasa do not effect the original. So if you have a 1000x800px file on your desktop called 1.jpg and you export it to directory in desktoptemp, you will have two files. The original un-touched file and your newly exported file in the temp directory. Now set the size and compression you want to use. For message board and general photos 800px is usually good. If it needs to be a large image or desktop image you may want to go to something higher like 1024 or 1600. The final option is the amount of compression you want to use. If you are using the windows version of Picasa I suggest you select "Automatic." For unix and Mac versions though you need to set a percentage. 85% is almost always a good compression. 100% is better but will make the file size considerably larger.
Movie on these steps: