If you are taking your girlfriends out on the ice, I'd suggest targeting perch. On really good days, you can easily catch at least 25+ "keeper sized" fish a day, per person. You can find them almost every where on Simcoe (although I've only fished the south end of simcoe for them). I usually find them in between 5 and 25 feet of water. I mostly fish for perch with a live minnow on a small jig head or by using small spoons.Try to move around to different water depths until you find fish.
You can also target pike while fishing perch since they tend to both hang around in shallow water. I haven't fished for pike that much, but a common method is to secure a large minnow to a set of two treble hooks and let the minnow thrash around under the hole. Remember that pike have sharp teeth so always attach a steel or very heavy diameter leader to any line intended for catching pike.
White fish and lake trout are a blast to fish for but are more challenging to catch. Both live in deeper water(50-125 feet on water), and having a fishfinder really helps. For white fish I think a common method is to dangle a small spoon with a minnow just off the bottom. For lake trout medium sized spoons, ice fishing jigs and lipless crank baits; worked 5 to 25 feet off the bottom, have worked for me.
Good luck and have fun.