Here is the latest in my link-listing series. Also check out my ASP.NET Tips, Tricks and Tutorials page and Silverlight Tutorials page for links to popular articles I've done myself in the past.
You can also now follow me on twitter (@scottgu) where I also post links and small posts.
DataAnnotations and ASP.NET MVC: Brad Wilson (a dev on the ASP.NET MVC team) has a nice post that describes how to use DataAnnotations to annotate model objects, and then use a model binder to automatically validate them when accepting form posted input. DataAnnotation support will be built-in with the next version of ASP.NET MVC.
Hope this helps,