Whitefish spawn in late fall and early winter, so at first ice, I would try shallow, hard bottomed areas. It is better if there is a tributary mouth nearby. (be very careful of current making dangerous ice!) On the lakes I fish, this is generally 15 feet or less. Whitefish are very skittish, so when you are in shallow water, you will probably need to black out the light in your shack, and be very quiet so as not to spook them.
Most of my luck comes on deep clay / sand and gravel areas.
I also like steep drop-offs ( the first real sharp break into the main lake basin) especially if there are zebra muscles attached to the rocks. Large rocks with Moss or small grass are even better. Mark them with your GPS.
White fish that are not suspended usually root along the bottom for blood worms and other bugs.
I like to catch them on a Swedish Pimple, with a couple of Wax worms or Maggots on the treble hook.
Whitefish have excellent eyesight, so use a clear mono or Fluorocarbon leader that is about 12" long, to a nice swivel.
Whitefish fight pretty hard. Notice the sharply forked tail. Fighting them from down deep is great fun, just make sure that your reel has a nice drag system and that it is set properly.
Whitefish have a very soft mouth, similar to a Crappie, and you can tear the hooks free if you don't take your time and play them right.
They fight hard, and will often tear hooks free when you are trying to lift them from the hole.
A gaff will help you get them in.
Hope this helps,
Wiener
