Some questions are easier to answer than others, and this definitely falls into the 'harder' category! Here was the question posed to my Facebook page: "How do you decide what light you need? I know when I am looking at a good "picture" but it never looks the same on my camera!" Oh and haven't we all been there? Since this is such a big topic, I'll try to break it down a little bit and answer basic questions. If there is something else specific you want to know, leave a comment!
It's a common misconception that photographers love shooting at noon. I will tell you now: we do not. Though it's true we love lots of light, we mostly love lots of filtered light. I would much rather shoot inside with light coming in the windows than outside with the sun overhead and no shade nearby. This is because the light can be so harsh - it's difficult to take a picture when your subject's face is SO bright that their skin just looks washed out, no matter what you do.
A few hours before sunset (and sunrise!) is generally a really great time to shoot. The sun has started to sink in the sky, and the light isn't as sharp. This will also give your images that nice, orangey glow that makes everything better! However, this isn't always an option if you're limited by time, so my basic answer is this: if the light is harsh, find shade.
Now, you don't want to go somewhere dark - that won't give good results either. But if it's noon and you're about to eat a family dinner and need to get a picture now, find some trees. Stand in the 'open' shade (not inside, generally) where there's still plenty of light. Make sure the lighting is even on each person in your shot. It will not turn out well if you have one person in the bright sun and one in the shade. You may have to change your white balance a little, depending on the camera, because skin tones are slightly more blue in shade, but it is so worth it! There should be plenty of light on your subject's face, without being too harsh or washing anyone out.
That's a basic, really shortened version of finding good light! I could talk for hours on it, but that should help you make sure your next family photo is a success. Let me know if you have any more specific questions, and check out some of my other 'how to' blog posts below.