Once and for all probability question(s)

There must be someone here who is knowledgable enough to explain to an idiot like me a SIMPLE way to calulate the probability of:

a). hitting one of your outs over the next two cards

b). hitting runner-runner (i.e. hitting one card AND another card) over the next two cards.

I know there are two ways to do this. One has something to do with figuring combinations. Another has to do with figuring out the probability of it NOT happening first. PLEASE.... Can someone help a mathematically challenged person here and just tell me how to do it for myself?

Thanks VERY MUCH...