In general, the Image data type of MS SQL Server is mapped to a byte property in you Domain Class. This array can easily be retrieved by the function ReadFile if you have the file locally. Otherwise, it can be retrieved from the HTTP Request by different file upload controls, including the Uploader control in Rad Controls for ASP.NET AJAX.
Unfortunately we don't have a full example for this process, but it's a good idea for a new sample that will definitely be considered after the upcoming release.
Do not hesitate to contact us if you have other questions.
the Telerik team