Route: MapMyRide — Strava. The entire route is also drawn clearly on trail maps: here and here.
Traffic: Light traffic in the morning along Cañada Road. Crystal Springs Trail is a bike trail. It is quite popular among walkers, joggers and cyclists. No vehicular traffic.
Climbing: Both Cañada Road and Crystal Springs Trail are gently graded. Great for beginners. However, the roads that connect them (Bunker Hill Drive → Polhemus Road → Crystal Springs Road) have some moderately steep sections.
Bike Trails: Cañada Road has a comfortably wide bike lane throughout. Bunker Hill Road and Crystal Springs Road are bike friendly, with light traffic. Polhemus Road has a bike lane.
Crystal Springs Trail is a well maintained bike trail except for a short half-mile section along Skyline Blvd, between Hillcrest Blvd and Larkspur Drive (clearly shown in this trail map).
Views: Gorgeous views of Lower Crystal Springs Lake and San Andreas Lake. See photos.
Water stops and restrooms? Restrooms are available at Roberts Market, the starting point. Restrooms are also available at four locations along Crystal Springs Trail. See trail map. No water is available at any of these locations.
Good time to visit? Any time of the year. Sundays are best because the County of San Mateo makes Cañada Road vehicle free from 9am to 3pm on Sundays. See Bicycle Sundays (Yelp reviews).