In Control Panel, go to: Tools & Utilities >> IIS Tools >> MS IIS Manager
Selecting a user here allows that user access to your account through Microsoft's IIS 7 Manager. Note that you also select which IIS Manager features to enable at the bottom of this page. Selecting features here will prompt a download the first time you connect to your site with IIS Manager.

In general we recommend that only experienced developers use the Microsoft IIS 7 Manager. If you have been working with it in your own Windows 2008 development environment, you're probably safe. If this is your first experience with Windows 2008 you may want to use the DiscountSP.NET Control Panel controls to do your necessary site maintenance.