Studded tires are necessary for ice. You can make your own, but Schwalbe makes the best pre-done ones.
Further reading:
http://www.peterwhitecycles.com/studdedtires.aspI have standard 700x35 tires and they have plenty of grip on just snow/slush.
Having breathable rain gear (GoreTex or the many cheaper and quite nice knockoffs like Marmot PreCip or Columbia OmniTech) goes a long way towards reducing wind penetration, keeping you warmer with fewer layers. Ditto for gloves. Boots can be insulated, but some around here use their favorite biking shoes with a plastic bag wrapped around their feet inside the shoe.
A balaclava is nice. A full face mask is nice if you're biking longer than 5K in temperatures below -15C or thereabouts. Personally, I'd wait and see where your individual comfort threshold is before buying.
As far as conditioning goes, the best advice I have is to bike every day, even if the rides are shorter. You may need a rest day here or there at first, but I find missing a day to be counterproductive. I might change my opinion if I've just done a century, but in general I really like doing a minimum of 15K a day.
Edit: And don't forget lights, since it's going to be dark most of the time you're out.
I wrote a blog post about this as well, and here in WI we had some pretty bad weather. I biked in a few multi-inch storms, a couple near white-out blizzards, and a few times at temperatures in the -25 to -40C range.
thegoblinchief.wordpress.com/2014/02/20/winter-biking-after-one-season/
Others around here are even more experienced than I am.