Silverlight, HTML5, CSS3, ECMAScript (or Javascript?) jQuery and the open sourced ASP.NET MVC3.  One of the ways to get started is to go over the very through Project Silk web based training at:

Treat as you would a paper book, this series of web articles covers the design, security and maintenance of a well designed web site that can make you money.

Also, make sure to include a process for your website will implement a mobile user presentation.  I have notices a number of new websites that don’t take that into consideration.  Ask yourself: “How often do I view websites on my phone?” 

Even if you are design phone apps like a crazy person, it is still important that you have a well constructed web site.