Almost every RAW file requires some degree of sharpening to counter the effect of blurring that occurs at some stage of image capture or image processing. But when do you apply the sharpening? 
In Camera Raw or later in Photoshop? The answer isn’t as straightforward as you might think.
Mikkel Aaland, author of Photoshop CS2 RAW (and of course responsible for the Lightroom Iceland Adventure), has published a tutorial showing you how to sharpen with confidence on the O’Reilly website.
listen in iTunes