A brief description of unit testing, with a more thorough walkthrough of how to mock using MOQ. The demo code can be found at http://1drv.ms/1kQJWhb

2. Your
Code
Test

5. [TestMethod]
public void Method_Scenario_Result()
{
// Set dependencies, build SUT, set
// expectations
// Exercise the SUT
// Check behaviour/state of SUT
// Check that expectations have been met
}
Assert
Act
Arrange

6. [TestMethod]
public void Method_Scenario_Result()
{
// Set dependencies, build SUT, set
// expectations
// Exercise the SUT
// Check behaviour/state of SUT
// Check that expectations have been met
}
Assert
Act
Arrange

7. [Test]
public void CreateNumString_TwoSimpleNumbers_ReturnsStringWithCommaBetween()
{
StringCalc sc = new StringCalc();
string result = sc.CreateNumString(1, 2);
Assert.AreEqual(String.Format("{0},{1}", x, y), result);
}

10. SUT Dependancy
Dependancy
Dependency

11. public class Sample{
private DatabaseThingie myDatabase;
public Sample() {
myDatabase = new DatabaseThingie();
}
public void DoStuff() {
myDatabase.GetData();
}
}