Hello, Eray here -- just wanted to give everyone a quick heads up on a white paper some partners recently wrote titled, "Application Templates for Windows SharePoint Services 3.0: Under the Hood." I think the paper does a good job providing a little something for everyone. The opening sections provide a great intro if you're new to app building, or apps on WSS in general. The later sections briefly cover the main tools for building on the SharePoint platform and also discuss a high-level methodology for approaching these sorts of projects.
Folks that already have experience with both topics (which is probably most of our readers) will want to skip down to the "Implementing Common Design Patterns" section, starting on page 15 in the printed version. Here, the paper outlines 5 common patterns found in collaborative apps. With each pattern, the paper details a possible implementation of that pattern on WSS. Examples include things like building dashboard pages and getting started with parent-child list relationships.
Hope you enjoy the paper!