There are a couple of options you have when working with ASP.NET and trying to use a templating solution. Whidbey version is supposed to support build in templating but we have been waiting for that for some time.
Here are a couple of options and some links to some articles that you might find helpful:
1. Create a table layout and put user controls inside the table layout for the header and footer and nav. I use this scenario on my own websites. Yes, each page has to have the table code in it, but if you keep to a fairly simple layout this should not be a big deal. If you are truly adverse to this option, there are some more advanced options below...
2. Create a base class that does the rendering for each page and inherit that base class on each of your pages to automatically do the rendering, and use a placeholder control for placing your content in the middle. I did use this option on one of my sites a while back but I liked the simplicity and quickness of using the first solution better for my own needs so I stuck with that. But if you understand inheritance this is a good option. Here is an article about it this option:
http://www.devx.com/dotnet/Article/18011
3. There are a bunch more complex solutions that you can use but I think for most applications one of the above two will suffice. If you have even more complex needs there are tons of articles out there on different ones and some prebuilt controls you can use for the rendering. So you will have to do a little digging for your specific needs if you need something more complex.
Hope that helps a little
