Serial Question

OK I’m a newbe but I need to start some where
I have a netduino, and a great program that works fine
I want to change the variables via serial port
So like in this example change the 5000 to lets say 120 and the 1000 to 300
I have no idea how to do this, is there an example I can look at.
tnx
example

namespace NetduinoApplication1
{
    public class Program
    {
        static OutputPort led = new OutputPort(Pins.GPIO_PIN_D11, false);

        public static void Main()
        {

            while (true)
            {
                led.Write(true);
                Thread.Sleep(5000);
                led.Write(false);
                Thread.Sleep(1000);
            }

        }

    }

Check the support section for lots of information on programming and the micro framework