If there's just one more ASP.NET 2.0 book you buy before the year is out then it should be 'Developing More-Secure Microsoft ASP.NET 2.0 Applications' by Dominick Baier. I haven't read the book cover to cover yet but chapter 8 - 'Partial Trust ASP.NET' alone should have you running to the bookstore to get this title if you care about securing your ASP.NET 2.0 infrastructure.