Is this a special kind of flour? Is it self rising flour or just plain flour?

Here's a great explanation....

http://www.wisegeek.com/what-is-cake-flour.htm

And in response to your self-rising query, it would only be if it contained a levening ingredient such as baking powder. Not all brands of cake flour on the market are self-rising, but some are. (The label will clearly show that if you happen to choose one that is.)