Now that I'm starting to get a handle on this fiddly business of web designing, I've noticed what a diabolical mess I've made of setting up the directory structure. So, I've pulled it all apart and put it back together again.
In the process I've made all the pages a bit more uniform and finished looking, and now you can navigate to any page from any other page (except the front page) - convenient! It's almost enough to create the illustion that there's actually a lot of stuff in here.
Let me know if anything's broken.