I think it's looking pretty goo so far. You can get plenty of suggestions here, I'm sure, but the most important input should be from your market. You want to know who they are, exactly what they want and give it to them.

I'm not sure if it's just my browser, but your sidebar is showing completely blank and a bit odd for that reason. You can do a lot with the sidebar area. I think if I were doing a site like this I'd go for a calculatedly cluttered look for pages. My favorite hobby shops have always been those with interesting things to see everywhere-- and stacked to the ceiling. Have you ever walked into a very sparse hobby shop? It's not nearly as fun. A hobby website probably has the same effect on a hobby buff.

I believe I had a Batmobile exactly like the one on your main page.