I use Lightroom at the beginning of my workflow and normally sharpen in Photoshop as my last step. But sometimes I need to just use Lightroom for a super quick edits and that is when I use sharpening in Lightroom instead of in Photoshop.
Here is my screenshot of Lightroom 4. The circled area is where the sharpening controls are at. (in the Details panel)
There are 4 sliders in the sharpening section in the Detail module.
The first one is the amount slider. This is the overall strength of the sharpening effect. Lightroom defaults this setting to 25 and it ranges from 0 to 150. The higher the number, the more sharpening will happen.
The second slider is the radius. This is basically controls how fine of detail is going to be sharpened. The larger the number, the larger the radius. If you go too big, you will get a halo effect, so don’t get too carried away!The default is 1.0.
The third slider is the detail slider. This will help reduce the overall halo effect. This one works backwards with the numbers. If you have the slider up at 100 (it goes from 0-100), no reduction in the halo effect. If it is set at 0, you will not have any halo. The default is 25.
The fourth slider is like the third. It masks out the overall sharpening effect. The higher the number, the more masking will occur. The default on this slider is 0.
Now, of course, I will let you know what settings I prefer to make this even easier!
I like to keep the amount around 50-86, the radius anywhere from 0.6-1.3, and detail from 22-30 and the masking from 0-49. These are definitely not perfect settings for all images, but it should help give you an idea of possibly where to be. It definitely depends on each image.
I hope this helped! Lightroom is always a quick and easy way to sharpen your images to speed up your workflow!