This article describes some features and architecture of IIS 7.0 and deployment of ASP.NET sites on IIS

This Link will Help You to see whats happning inside IIS7.0 although 7.5 is in the market but base is this so must read this link below

http://www.codeproject.com/KB/aspnet/IIS7ASPNet.aspx

@Gaurav_TarnTaran