Joe, If your pictures are 500 pixels wide (or tall, for vertical shots), 72 dpi (dots, or pixels per inch), and saved in JPEG format (at about 60 percent compression or ''quality'' rate), they should turn out less than 80 k.
You need to use an image editing program to make them fit the above criteria. There are several available (you may even have one that came with your digital camera or scanner). Some use Irfanview. I use Photoshop LE (light edition).
Does this help? We discussed this not long ago
on this thread. There's also some info in the Website Tutorials section of the Forum.