This post has the steps to set up remote debugging of IIS 7.0 web sites with Visual Studio 2008.
Last time I wrote about debugging on IIS 7.0 was Fix problems with Visual Studio F5 debugging of ASP.NET applications on IIS7 Vista. Since then, a hotfix was released for Visual Studio 2005 that makes debugging IIS 7.0 applications easier, and solves the problem of debugging on Vista Home Premium which does not have the Windows Authentication component of IIS 7.0.
Now, with Visual Studio 2008, debugging IIS 7.0 has gotten easier. In fact, debugging local apps is a breeze, but there are still some gotchas you may experience when trying to debug remote IIS 7.0 applications.