Study sure. But if you use LR and have to process images, then that's unnecessary. Learn to use the camera to produce well exposed raw data. I recall spending decades doing this on film when few if any photographers had heard the word Histogram! Then normalize in LR and move on. The histogram is the histogram and histograms really don't provide much info that's useful other than clipping, which LR will easily show you on the actual image. Far more useful to SEE on the image what clips and where then trying to decipher a histogram. At least if your goal is to produce a pleasing image. For some scientific or analytical work, by all means 'study' the histogram.
LR/ACR, at least with PV2012 and the default tone curve, is not good for evaluating overexposure since automatic highlight recovery is employed and an exposure offset is used. With Nikon cameras it +0.5 EV for the D3 and + 0.35 for the D800e. With ACR one can get a reasonable representation of the raw file by adjusting exposure to offset the baseline exposure value and using a linear tone curve by setting the sliders on the main page all to zero and setting the tone curve to linear. Added in edit (3/18/2014). One must use PV2010 when using this method.
Rawdigger can show overexposed areas as well as the rendered image, and is not limited to presentation of the histogram.
Here is an image taken by the D3 with overexposed yellows as shown by Rawdigger:
And by ACR with the required adjustments. I should have rendered into ProphotoRGB to prevent saturtion clipping rather than into Adobe RGB, but the clipping is reasonably shown.
Here is another exposure that is not clipped in the raw file as shown by Rawdigger:
However clipping is shown in ACR even with the above mentioned adjustments. The clipping in the red channel is likely due to white balance with a red multiplier greater than unity. The green channel shows spurious clipping in ACR.
I agree that Rawdigger is the preferred tool for evaluating raw files.