This book page should hold notes about themes. I watched the dudertown videos 11 and 12 about themes and I think they're really not too hard to follow if you've ever seen CSS before. If you haven't seen CSS before and are interested in web design at all, do yourself a favor and learn about it. It's a way to separate the look and feel of a site from the content, allowing you to change the entire layout of a site based on one page of code.
I substituted the 'chameleon' theme with the 'foliage' theme and replaced the main images. I did some work to change the color scheme to greens, but wasn't happy with what I ended up with and didn't have any more time.
The colors may not be exactly what we're after yet, but they were very readable, so I wasn't going to tweak them too much yet. I grabbed a page out of the Book of Kells for the banner image. I'm sure we could find something more suited to our period (the Book of Kells is from about 800 A.D.), but it gives the impression of ancient Ireland in a powerful and readily recognizable way. Without more active collaboration with you folks, I'm afraid you'll just have to deal with whatever I come up with.
How it works:
You just grab a new theme from drupal.org and drop it into the themes subdirectory, it instantly becomes available in the administration page, you enable it and you're done. You can customize the css that points to images (as shown at the top of the page and the bottom), or all the colors and the fonts used by editing the style.css page in the theme folder.