Ride the Abyss Trail. It's got a great mix of singletrack (some double track), rocky climbs, rock n rolls, rock'n hucks, ups and downs and views of the ocean. Here's a map:
http://www.island.net/~pmcgarri/abys.pdf There are other trails you can connect and make it a loop ride for a few hours. Park near the trailhead off of Harewood Mines Road. There is a steep dirt/rocky section at the beginning to climb up. (The BC Bike Race included the Abyss Trail this year.)
I think it would be a dog-friendly area but check with a local bike shop (Arrowsmith Bikes 250-758-6675). Keep an eye out for motorbikes and ATVs as these are seen more often than not poaching the singletrack sections of the trails.
I just wanna ride my bike.