Here is what I have to say about font pairing: Don’t do it unless you really know what you are doing.
Typography is really hard. Choose just one font family and you can’t go wrong, even if that typeface is comic sans.
Remember to pick one that has several styles. Then create contrast by changing the weight.
What if I want to it anyway?
So, if you really want to get into font paring and you don’t wan’t study typography for years: copy from someone else.
Typekit has an excellent gallery to get “inspired”.
If you want to go Google fonts way (and you should) check Google type project.
Beautiful web type has some very nice examples on how to use font on the web.
And always remember Picassos words:
Good artist copy great artist steal
There you go Bruno, I’ve already told you all this a few minutes ago, now it’s written.