I know that Keychain holds my WiFi and other passwords, but I'm curious to know where my Adobe and Microsoft product keys for things like CS6 and Office live. I'm using OS X Mavericks.
There's no generic OS X place for storing product keys. It is up to each individual software supplier to decide where they want to store the products. Usually it is done in ordinary files stored in the file system.
For Microsoft they reside in /Library/Preferences/ under a name such as com.microsoft.office.licensing.plist.
Similarly for Adobe I think they are in /Library/Application Support/Adobe// Registration
As a user you don't really need to know where it is stored as the programs handle product key management themselves.