Alright. So I'm fairly new to C#. What i've down thus far is create the beginnings of my program:

            using System;

using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace WindowsFormsApplication1
{
public partial class BirdNumber : Form
{
public BirdNumber()
{
InitializeComponent();
}

    private void BirdNumber_TextChanged(object sender, EventArgs e)
    {


    }

    private void SessionNumber_TextChanged(object sender, EventArgs e)
    {


    }

    private void dateTimePicker_ValueChanged(object sender, EventArgs e)
    {

    }

    private void Habituation_CheckedChanged(object sender, EventArgs e)
    {

    }

    private void Autoshaping_CheckedChanged(object sender, EventArgs e)
    {

    }

    private void TITraining_CheckedChanged(object sender, EventArgs e)
    {

    }

    private void TITesting_CheckedChanged(object sender, EventArgs e)
    {

    }

    private void StartButton_Click(object sender, EventArgs e)
    {



}


}

}

What I want to do is have the StartButton, when clicked is record which radiobutton was clicked as well as data from the 3 text boxes into a textfile.

I've googled many possible answers, but none of them seem to do all that I want. Any suggests?

I can provide more code if necessary, but it would just be the form.designer.cs code.

`

But what you will find when you Google are answers that handle part of what you are trying to achieve. Break it down into the steps:
Determine which radio button is clicked
read data from a control (your textbooks)
write to file

Each of these things can easily be googled and then put together to give you your complete answer.