I see you were having trouble with adding binding, but that was a few years ago. Have you figured it out? I, too, saw that she didn't show where to start sewing the beginning of the binding. When I start, I press a triangle into the beginning of the binding strip, fold it in half and put that triangle near the center of one edge of the quilt. Put a pin about 6 to 8 inches on EACH side of the point of the triangle. Now start sewing 6 to 8 inches down from that triangle, at the first pin. When you come around to the end, stop sewing about 12 to 16 inches from where you started sewing, at the second pin. Lay the quilt out flat and lay the two ends of the binding as you will want to sew them. Cut the ending strip of binding at the base of the triangle you pressed in at the beginning. That is your measure. The two strips overlap each other just the right length: the width of the binding. Now pick up the two ends of the strips RST. Twist them so that they look just like any other seam you have made in your binding. Be sure the crease in the triangle goes side to side. (You may have to twist the other way.) Sew this seam on the triangle crease.
When you get the hang of this, you'll wonder why you ever did it any other way, and why someone didn't show you that sooner.