For a completely free and easy to use screenshot capture, you should give Open Source Greenshot a go. It easy to use and has some advanced features like auto filenaming, save directly to file. When you do the capture, you get a crosshair and the area you selct has a green tint (aka Greenshot I guess) and you can see how many pixels you’ve captured.
Here’s a selection of screenshots from the prog
This program covers my needs for a good screen capture program. I’ve used a couple og others like MWSnap and GadWin Printscreen, but I think this one is easier to use. I’ve never used Snagit myself and understand it has some extra features, but it costs about 50 bucks, and to capture a couple of screenshots from time to time it seems a lot.
If you really dig it consider donating, but this is open source and freeware so you’re not obligated.