Welcome to the Guild Impulsenine. I agree with Korash, sounds like you already have the tools and the expertise to create lovely maps, but perhaps are just casting about for a bit of inspiration. Well I'd recommend browsing the finished maps section to get a taste of the various styles of fantasy maps and perhaps to give your wife some styles to choose from. Even if you are skilled in Adobe Sweet the tutorials section is worth checking out since you might pick up a few tricks you didn't know previously, or at least see how to apply what you already know in a new context. Best of wishes on your project, and please post up your work for us to see.

Cheers,
-Arsheesh