How do I change cake recipes for cupcakes? This is a three-part question:


Which classes of cake are unsuitable for cupcakes?  Can I do angel food cake or pound cake?
What changes do I need to make when converting a normal cake recipe for cupcakes?  Temperature or baking time changes?
Roughly how many cupcakes should I expect from a recipe scaled for a 9x9 pan, a 9" springform pan, or a 12 cup Bundt pan?  I'm not looking for precise counts, just a rough estimate to the nearest 5 cupcakes.
I've not yet found a cake recipe which I could not use for cupcakes instead.  
I always change the baking time and only the baking time.  I rotate the tray of cuppies after about 7 minutes, and after another 7 minutes or so I use the "clean toothpick" method to see when they are done.  
It does vary greatly, but from most cake recipes, I expect to get 18-24 regular cupcakes, about 40 mini-cupcakes, or 9-12 large ("Texas") cupcakes.