We have a number of very talented artists here, and some good general ideas about how to tie the pages together. Besides looking good, our main goal is to get visitors to the front pages interested enough to come in and spend some time in the forum. And hopefully join.

Please note that I'm purposely not responding to some individual ideas, because the purpose here is to generate as much discussion as possible amongst members. Likewise, I don't think pj or the other admins will, since we don't want it to seem like the matter has been at all settled when we say this or that idea is good (or not.) Everyone's suggestions carry the same weight.
As far as web design goes--it's completely unnecessary to understand the first thing about HTML, CSS, etc. to "design" a site. Those things are used to implement a site, and I have enough knowledge to attempt to implement the ideas that come out here. Think of them as the raw materials artists work with--anyone can learn to use them, but only those who have a vision will be able to create something beautiful. What we need is vision--those with artistic minds to imagine how things should appear. We can handle the actual implementation.
So, artists: besides images, there's the question of the layout of the entire page. It's an entirely visual thing. Where should the menus appear? What should the little things like the boxes containing forum stats look like? Do they have borders, images, etc. around them? What we need, really, is an image of the entire page. That's 90% of web design. (Of course, the design should also be practical and usable.) This is the hardest and most important part; the rest is just code-related details I can handle.
All this will take some time to do right. Hopefully enough people will be involved that a sort of consensus is reached. In the meantime, please don't think your ideas are being ignored because they've not been acted on right away. They're most appreciated. Thank you!