SQL and Visual Studio Retrieving a Table

Hi - I'm trying to select all the "emails" in a table called "users" with c# in visual studio. Currently I have this command:

SqlCommand cmd = new SqlCommand("select email from Users", cn);

SqlCommand cmd = new SqlCommand("select email from Users", cn);

I'm not sure how to get the data from this though, would it be doing smth like:

List<string> emails = cmd.Execute();

List<string> emails = cmd.Execute();

SQL and Visual Studio Retrieving a Table - C#