ok...so,winter tires are a kind of enigma to you guys, right?
here in croatia we have 20-50cm of snow every year. sometimes it last for couple of days, and sometimes it lasts for a month, with lots of ice. then i can do this:
http://www.youtube.com/watch?v=KH0o_mQMlYc

as for the tires...you can manage with good set of summer tires, unless it is icy, or you have to get up a steep hill. HOWEVER, it is sooooo much easier to drive on snow tires. while others struggle to accelerate on summer tires, you don't even feel the slippery.
tip: get a set of steel 15'', buy a set of 195/65 r15 M+S snow tires, and then wait for snow....you will have a time of your lives
nokian produces great snow tires.
here, we usually buy SAVA ESKIMO S3...with price around 40€ per tire (195/65 r15) it is a best buy.
one more thing: NEVER buy a all-season tire...they are crap all-year-around

ps: winter tires need to be NARROW...so they can drop through the snow to something solid (asphalt or harder layers of snow)...