Photoshop Unsharp Mask...
Amount: 300
Radius: 0.3
Threshold: 0
is a pretty standard way of doing it. Just experiment and actually print it - the visual effect of sharpening is different between screen and print.
For the book, I'm having to leave sharpening to the publisher and I'll be livid if they get it wrong or don't sharpen at all (which would meke investing in 'L' lenses utterly pointless...)
Have look at this -
http://www.luminous-landscape.com/tu...ding-usm.shtml - understanding what it all means might help a bit.