Gord from Elliot Lake, Ontario asks: "What is the best way to fasten baseboards when you have metal studs and base plates?"
Often workers will add a piece of wood into the floor track to allow for nailing of the floor boards. If you don't want to double up material like that, then you should use what are called "trim screws". These are #6 screws with extra small heads specifically designed for attaching trim and puttying over the screw heads. They will screw well into the metal base track, eliminating the need for a wood backer in the track.
Similarly, if you want to hang heavy cupboards on a steel stud wall, you should install wooden backers at appropriate positions inside the vertical studs before closing in the wall. This will allow screws to go through the steel stud and bite into the wood on the other side, distributing the weight across more of the steel stud and avoiding tear-out.