Most of the lakes up here have trout, but they can be picky.
Beaver, just off the Port Alice highway at the junction w/the Port Hardy highway, is a good one to start and close.
If you have a truck or good car/SUV w it decent tires, the Benson Lk circle route is a good one to try.
Three Isle, Keogh, Benson, Trout lake and a few ponds along the way all offer trout fishing, some better than others. The bigger lakes like Alice, Victoria and Nimpkish are too big for float tubing, but lots of smaller ones will work. Do not forget the beaver ponds as they hold some good cutty fishing.
Like Springnut said, get a Back roads book and also stop by the WFP office and grab one of their maps (if they still have them).
Cheers
SS