Hi Karen,
Welcome to the Q&A Board. Your website is lovely and I think you've done a fine job at capturing detail in the photos. The images I looked at are well-exposed and look well on my monitor.
Someone may come along and have a different opinion but I personally don't think taking photos and scanning them will produce better results. What I would suggest is that you shoot the images at one megapixel, highest (best) quality when you know the images will only be
used on a web page. This way, you won't have to reduce the images so much.
Taking large images and reducing them to a much smaller size can be a challenge. When I reduce images, such as when I create the header graphic for a contributing writer, before I reduce an image, I sharpen it slightly. Then I resize the image and do any additional
retouching that may be needed (eg. adjust brightness, contrast). My final step before "saving" is to sharpen once again. I use Unsharp Mask so I can control the degree of sharpness applied.
Here are some examples:
http://digicamhelp.com/about/deb-tappan.htmhttp://digicamhelp.com/about/mike-farslow.htmAs I'm sure you know, compressing an image too much can degrade the visual quality. Your images are small so, in order to get even more detail, you may not have to compress them as much as you have been.
While not specifically related to small sized images, you may find some of the information useful in this article about resizing images for web presentation.
http://digicamhelp.com/learn/image-editing/image-resizing-for-web.htm