How exactly do u apply mineral foundation?

hi, i purchased some rimmel london mineral foundation and its got the sponge on the top, i know its powdery but im not really sure do i like "smack" it on my face run it on my face? because i cant really see a difference lol not really sure how to use it:P any help would be great as its my first time using this kind of foundation and would u use it ontop of rimmel match perfection liquid foundation?? as ive got that one as well lol thanks