Dynamic Page with Dynamic Controls

This will not be a one step task.

1. Creating a website for each user is not a problem. What you will do is, create a new folder in the existing website folder or another folder and copy all pre-created files to that folder.
2. After that you need to make that new folder as a virtual directory on IIS so it can run as a Website.
3. As per each site having its own user can be managed in different ways. One way is have each user website its own database and have its own registration process.

Hope it gives you a direction to think about in.

Cheers!