What you could do is trace it with the pen tool, right click when it is done, click on "make selection" and that will give you a selection of the area you just traced. Another option is to use the polygonal lasso too, thought I have personally not had much luck with it.
Regular pen tool. If you zoom in you don't need to bend the anchor points because they will be so small anyway. After you've finished one path, right click and click "fill path" and then "delete path" to get it on a normal layer.
Excellent tutorial! I am very comfortable in Illustrator, but not so much Photoshop. This should help me get out there some more. Just one question: is the pencil tracing with lasso? I have always just used the Pen tool and regarded the Pencil something relegated to rough sketching.