I will be leading a team to create a complex manufacturing web app in ASP.NET (web forms) soon, and previously our business logic would be in the same project, or even worse, in the code behind of the page.

I understand that seperation of concerns is important, and makes testing much easier (testing has always been a problem of ours), so this is the direction we want to go in.

I'm a bit confused about how this can be implemented however - we use a lot of RadGrid's etc which we bind to SqlDataSources. How would things like these work with all of the business logic in another project?