What is a web part?
Web Parts are components that enable users to gather information they care about and customize the appearance of Web pages in MOSS environment. For example, visit Pageflakes website, where one Web Part might display a user's appointment calendar; another might create a graph showing current sales figures; and a third might show a list of new business topics, each of which functions as a link to a video or audio presentation. Developers can also create custom Web Part components and make them available to SharePoint users, for building customizable pages that meet their needs.
- Introduction to ASP.NET 2 WebPart Framework
- Web Parts Control Set Overview
- Example - creating a web part with deployment http://www.developer.com/net/asp/article.php/10917_3620316_1
- Lynn Langit blog