I've started reading this list. Jisses! There's is literally a ton of links to excellent resources here!
I'll work my way down the list when I have some more time. However I found this, seems like it could have saved my a lot if I'd known about earlier. It's a package with validation controls for ASP.NET for every situation. Looks really good.
This seems like another usefull resource. Loads and loads of different date controls. I'll have to remeber this site the next time I'll nedd one.