Quote Originally Posted by Asylum Steve
As a photographer you need to compare the histogram with your perception of the scene (IOW how you're trying to depict it) as well as your light meter readings...
This is the absolute very best piece of advice about histograms. You should get to the point eventually that you'll know what the histogram looks like (well, pretty close at least) before you even see it. When it consistently looks like what you want it to look like, then you're good with exposure. A lot of my band pictures have blocked up shadows and have no detail past the center of the histogram (very little at that point, too) and - to me - that's how they should look. A smooth histogram that spans from one side to the other ain't gonna happen, and won't look right anyway.

Bottom line, the histogram is probably the most valuable tool on a digital camera - as long as you learn how it works.