When time permits (not often lately) I run the pics trough a simple photo editor and brighten them up. It is amazing sometimes, how much detail is then available. Many of the Russian sites have horrible control of light and shadow. I use a basic editor downloaded for free from one of the free computer magazine download sites.
I use Photoshop, but there's many other softwares. Paint Shop Pro is often used and I heard good things about Faststone (faststone.org). You can also look the bundle included with almost any new digital camera.