I recommend that you look over Jason's website and be sure to subscribe to all the resources that he uses in his tutorials. That will make doing these small projects much easier to accomplish.
Below is a video that explains how he uses the pencil tool to create wonderful cartoon-like drawings using the pencil tool. In order to access the settings that he's using you will need to double-click on the pencil tool itself in the toolbar. I would recommend watching this video in the YouTube environment - it will allow you to go full screen and see things better. The URL for the project we'll be working with today can be found here.
I've attached a simple drawing that you can use to try these techniques out.
This is the file he's using of the muffin man.