I ride in the winter with Schwalbe Ice Spiker Pros in a 29x2.25 size. They have about 400 studs per tire and are exceptionally good in a variety of icy conditions. I ride mostly easy single-track, dirt roads, and bike paths near my home. Stud count is important. I tried tires with lower stud count than the Schwalbe and found them to be unsatisfactory.
As others have mentioned, the areas to be careful of are icy ruts and steep hills. Footprints frozen in ice are okay as long as you maintain momentum. Ride smoothly and avoid sudden changes of direction or grabbing the brakes too hard.
The other thing you need to consider are your shoes. If you put down your foot on glare ice, you are going to go down. There are some winter boots out there that allow you to add studs similar to what are in the tires. An easier solution is to buy socket hex-drive sheet metal screws and insert them into the soles of your boots. Just remember to take your boots off before you walk into your house.