Continuing from another discussion, I prefer using Unsharp Mask for sharpening. I've used it in Photoshop versions 7 through CS5. For web images (around 1000 pixels on the longest side), I use Threshold 3, with a radius of 1.1 to 1.4 pixels and an amount of 50% for some cameras like K20D or K-5, and about 75% for a Q. DSLRs have +1 sharpening in-camera by default.

For A3 prints, I use a larger radius (around 2.2 pixels) and sharpen at 100% to 125%. Other sizes fall in between these values. I aim for sharp web images and prints without excessive sharpness.

Sometimes, I convert to LAB mode to sharpen only the black and white channel, preserving color information. Afterward, I convert back to RGB for printing. In recent Photoshop upgrades, this intermediate step seems less necessary, likely due to improved algorithms.