Here’s a good, pretty simple video on how to use that crazy histogram on your camera or in your photo editing program.
Many people say to “shoot to the right” which means lean towards a lighter exposure, which would have that hump nearer the right side. (this applies to RAW files that you will post process and not as much to jpgs) This is generally a good idea as opposed to making a darker exposure because you’ll get a cleaner (less noise and artifactings) image if you have to darken it some rather than lighten up the shadows/darks. In digital cameras, there’s usually more image data available to recover in the lights than the darks. Just don’t go too far and actually blow out the whites or block up the blacks, because you can’t recover that at all. It will just turn light or dark gray depending on which way you went too far. You can go past the right end of the histogram a little bit (though you can’t tell how far) and still recover some of the highlights, but that’s just something you’ll have to experiment with to see how much you can recover with your particular camera and RAW processor.