Here are the three (well, four) best resources for creating classic font combinations that we know of:
- The Big Book of Font Combinations (our book)
- 29 principles for making great font combinations (our big list of principles)
- 14 Top Typeface and Font Combinations Resources (our big list of resources)
The resource page has pretty much all the classic font combination pages and resources from over the last decade. If you start there, you are going to get all the info you need. There are other more modern sites that focus on examples rather than principles, such as I Font You, but they tend to be a bit random. A book like The Big Book of Font Combinations takes a systematic approach and limits itself to a core subset of the most popular fonts of all time.
BONUS REFERENCE: You can also find many of the classic fonts, pre-typeset and mixable on the fly in, our iPhone App, Font Combinations 2.0.