Welcome--MAC uses the term mineralized skin finish to refer to baked powders--you can use them in lots of different ways depending on your skin tone and they come in different colors for different uses. Some are highlighters, beauty powders, or even bronzers, but the use varies with the powder and the skin tone. so your question isn't super easy to answer, because it sort of depend on a lot of different things. If you look at these reviews, you can see how the Osborne ones look applied to skin--->
http://www.makeupandbeautyblog.com/mac-makeup/mac-sharon-and-kelly-osbourne-collection/ and
http://www.temptalia.com/mac-refresh-mineralize-skinfinish-duo-reviews-photos-swatches Once you get used to them, you can figure out how to make them work best for you, and which ones work with your skin tone. But if you are just getting started try to be patient. If I were in your shoes, I'd get a demo at a local store or counter to see if you like these and their effect on you before you buy. MAC has some that are permanent as well.