On this video tutorial Aaron Nace from Phlearn demonstrates how to use the pen tool in Photoshop.
The pen tool is the most advanced and accurate to make selections in Photoshop. It will take you longer but if you need maximum accuracy – this is your tool of choice. The pen tool is similar in some ways to the lasso tool but it is much more flexible. It creates paths which you can change in any time – these paths help you create selections – either straight or curved. It can be a bit confusing initially but playing with your points a bit will show you exactly how to control the shape.