The Island is a pretty nice place-thats why we moved here. There is one main highway (19) going north from Victoria, and it tends to be quite busy, but has good shoulders. There are other secondary roads you can take for much of the trip that avoid Hwy 19. Are you planning on visiting the Tofino?Ucluelet area? It is nice over there, but the road doesn't seem great for cycling (narrow, winding, and no shoulders), especially in summer with the tourist/motorhome traffic. If going to Tofino, I would recommend taking riding to Port Alberni, and taking the passenger boat "Lady Rose" to Ucluelet. It is a beautiful boat trip also.
There are maps available showing the recommended secondary routes from www.cycletouringcanada.com
(on the self-guided tour page.)
Maybe we'll see you on the road later on.