I've talked a bit about why I restore images before, and, in a recent issue, covered the research process I go through to find the images.
But perhaps I haven't really shown how big of a role researching images alone plays in improving Wikipedia. Even if you feel image restoration is beyond you, it's often not particularly hard to improve Wikipedia in a substantial way by research alone. So let's not just look at images before and after restoration — let's look at what was in the article before the research.