I've had several people email me and ask if I could do a video covering the fundamentals of creating a Web Service using the .NET framework. Since I enjoy working with Web Services I decided to make some time and do that.
The video discusses how to create a Web Service from scratch but also discusses some of the pros and cons that you should know about. For example, many people will return a DataSet from a Web Service. While that works, it's not very interoperable with non-.NET clients since the generated WSDL will be quite vague about what the Web Service actually returns. By creating custom types (classes) the WSDL can more accurately show a client exactly what they're going to get back. I've also seen many people put all of the code for a Web Service into the Web Method. That works, but you can achieve better code re-use by creating distinct layers for business and data functionality. These concepts and a few others are discussed in the video. Other topics covered include consuming a Web Service from an ASP.NET Web Form.
Thanks to Orcsweb for hosting my website (http://www.xmlforasp.net) and for giving me space to host videos! If you're looking for a host I highly recommend them. You won't find better service anywhere.