1. User Interfaces in C#: Windows Forms and Custom Controls by Matthew MacDonald.
2. Applied Microsoft® .NET Framework Programming (Pro-Developer) by Jeffrey Richter.
3. Practical .Net2 and C#2: Harness the Platform, the Language, and the Framework by Patrick Smacchia.
4. Data Communications and Networking, by Behrouz A Forouzan
5. Hacking: The Art of Exploitation, 2nd Edition by Jon Erickson (Jan 11, 2008).