Easy but with a couple little catches. If you need to do this, I recommend reading the help on the various properties of ProcessStartInfo. This code runs a console window that is visible to the user. There is a way to run commands by cmd.exe without actually showing a window... and I'm sure you can figure that out if you're interested enough. This should getcha started.
//set up to show a console window and send input to it
string pathToCmdExe = Environment.GetEnvironmentVariable("COMSPEC");
ProcessStartInfo psi = new ProcessStartInfo(pathToCmdExe);
psi.RedirectStandardInput = true;
psi.UseShellExecute = false;
//open the console windown
Process console = Process.Start(psi);
//send it a command
console.StandardInput.WriteLine("dir");
//TODO: Send more commands, read the results, etc.
//close the console window
console.Close();