That should be easy:
Visual studio is only used to create an assembly for the selenium test script that Nunit can use.
Follow these steps:
a) Install the prerequisties - along with Selenium RC. This includes JRE (Java runtime environment), NUnit, and Selenium IDE plugin for FireFox.
b) After installation - Launch the Selenium IDE plugin.
c) Open the page that you want to be tested in Firefox
d) Do your UI movememts on the page that loads.
e) The actions are recorded in the Selemium IDE.)
f) Stop Recording. The steps are all captured.
g) Choose Format from the Options menu. And "C#" as the format.
h) This gives you C# code.
Open Visualstudio and create a project. Create a class file and place this code.
Note that you now need to add references to the Selenium and Nunit libraries
a) Nunit.core dll
b) Nunit.framework.dll
c) Thoughtworks.Selenium.*.* dll's
Compile the project and create an assembly.
Start the Selenium RC Server using the java command:
java -jar pathToTheSelemiumServerJarFile
Launch the Nunit program and open the compiled assembly above.
Click "Run" to run the test.
That's it.