Help in modeling a human head (nose part)

Hi, I’m a newbie in 3D modeling and I’m posting to ask for help on a few things. First and foremost, I am trying to model a realistic 3D head and I am using the book “Introducing Character Animations with Blender” by Tony Mullen.

I’m at the part where the author writes, “To create the nose and nostrils, you extrude the region formed by the five faces from the current tip of the nose and draw them forward along the Y axis.
After doing this, move the resulting vertices into place to form the shape of the nose.”

I’m having a bit of a trouble trying to understand what he meant by moving the resulting “vertices into place”. Where do I move the resulting vertices? and also, How far do I extrude the region?

Here’s the current mesh:


Bit of a shameless plug but you can check out my face video tutorial at my website:
It covers the whole front of the head from scratch.

thanks, just what i needed