Combining netduino with Ethernet Shield
I got my my Netduino plus recently but have not had a chance to work with it yet. I did also buy a book about it: "Getting started with the internet of things" by Cuno Pfister, an O'Reilly publication. 

I can tell you what the book says are the requirements:

1) Microsoft Visual studio 2010 or newer. The free Visual studio express is sufficient. However you need to install the C# edition.

2) Microsoft.NET Micro Framework 4.1 SDK or newer

3) Your developement boards SDK and drivers.

All of these are free. It would be interesting to hear of your progress. Good luck!