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I stand by what I wrote earlier about web sharpening - basically that web images are usually low resolution and therefore the sharpening can afford to be less subtle. However, if you want to sharpen other images in Lr at full resolution then you have a few controls to work with. Unfortunately I have found no sure-fire approach to general capture sharpening other than to apply whatever has worked previously for the same or similar camera at the same ISO (and even then hope that the exposure compensation was not spoiling the result).
I tend to use a small radius such as 0.7, though bigger for low-res images or if the details in the image are large and simple.
I use an amount of about 60 at low-ish ISO and down to 40 at higher ISO, but the need to reduce the amount varies with the amount of noise reduction applied and the amount of masking applied. Less noise allows greater sharpening without artifacts caused by the noise. The high amount is acceptable with a small radius but would probably be excessive for a larger radius.
I use a detail setting of about 60-70. The default value for detail is too low but once it is high enough there seems to be relatively effect compared with Amount or Radius.
I use about 20-30 for masking unless the image is noisy and/or has lots of featureless areas such as sky that shows artifacts if the Amount is high, and then I'll increase the Masking. Too high will undermine the sharpening.
After doing all of this I'll look at the edges of fine details to see if there are signs of artifacts such as a ragged edge that ought to be straight. If I find it then the two most effective solutions are to decrease the Amount or to apply noise reduction. I'll avoid the NR solution if the ISO is low because it should not be needed at low ISO, but I'll prefer NR at high ISO because it is generally required with or without sharpening.
When I've got settings that work I'll make a preset for that camera/ISO combination so that it becomes the new default settings for future photos. However, being unique for each ISO means there may need to be a lot of presets.
My experience suggests that my 1D4 images withstand less sharpening and need more NR than my D3s images. The 1D4 is inherently noisier. The D700 images are much like the D3s in terms of sharpening except at the higher ISOs where less sharpening or more NR is required.
Note that this all applies to capture sharpening - making the image look sharp on screen at full size to compensate for the Bayer RGGB digital sensor pattern and demosaicing process that is inherent in nearly all digital camera images. Something quite different is needed for artistic effects or to adjust for print output. For example, if the sharpening looks good on screen then it almost certainly will be inadequate on a print, and what is good for prints will look crappy on screen. However, while Lr 3 will let you see capture sharpening in image previews at any size it will not let you see print sharpening except in a special print preview. What you see most of the time when browsing or editing in Lr Library and Develop modules is capture sharpening.