Layers Magazine posed a great article awhile back, helping you step by step to pick a winning font combination.
Font combination can easily be one of the most frustrating, & yet rewarding elements of design. Finding those several fonts that look great together can take time. Often, taking more time than we can afford when you have deadlines on your calendar. In these situations, there are a few quick tips that can help you along the way. So if you take nothing else from this article, remember the following ‘golden rule of font combinations’.
Choose either typefaces that will ‘concord’ or ‘contrast’ but never ‘conflict’.
In other words: to stick with fonts that are solely within the same typeface would be to ‘concord’, & choosing fonts that are entirely different – serif & sans-serif, for example, would be to ‘contrast’.
Other elements to consider:
You can read the full article here.
Really in a pinch? Check out this list of fool-proof font combinations by Douglas Bonneville.