Notice that shingle rows are straight and shingles are laid correctly. Look at your house or neighbors and see if the shingle is straight. These are GAF Timberline HD Charcoal Shingles.

Weatherwatch is an ice shield used in the valleys to protect against ice damage. If you do not have this, you can have a leaky roof. If you are getting a new roof, make sure they use this. 

Roof vents are essential because they allow the heat to vent out of the attic in the summertime, save on electricity bills, and keep your house cooler.