In reply to puppythedog:
A set of wires, three or four hexes, a few friends, (be careful of these in icy cracks,) a few smaller pegs, four or five screws, up to ten quickdraws, (useful to take longer ones or tripled up 4ft slings,) and some long slings will get you up most things up to grade IV.
If it's a Ben style ice route take more screws, if it's a Gorms style snowed up rock route maybe take another set of wires.
Once you've done a few routes you'll get a feel for what rack to pack for which area / route type / your comfort level, but to start with I would say it's better to have too much than too little.
Expect to place less gear than in Summer on most routes.