Lightshot

Click the taskbar icon or hit the Print Screen button and Lightshot will take a screenshot. The application will then allow you to annotate the screenshot – draw on it, add a piece of text, highlight areas, and so on. When you’re done, you can copy the screenshot, save it locally, upload it to the web, or share it on social networks. That is, in a nutshell, the sort of functionality you can expect to get from Lightshot.

Lightshot is available as an installer for Microsoft’s Windows operating system and for Apple’s Mac OS X.
Lightshot is also available as a browser extension for Microsoft’s Internet Explorer, Mozilla’s Firefox, and Google’s Chrome web browser.

While Lightshot is running on your Windows-powered machine, you will see an icon in the system tray.
Right click the icon and you will be presented with a context menu that features the following entries: Sign In, Take Screenshot, About, Exit.
Left click the icon and you will be able to take a screenshot. Alternatively, you could use the Print Screen button to achieve the same effect.

First up, you must select the region that will be captured. Select a rectangular area and Lightshot will take a screenshot of that area.
Next up, you can annotate the screenshot: draw using a pencil, add a line, add an arrow, add a rectangular box, add some text, use a marker.
And last but not least, you must choose what you want to do with the screenshot: save it to the location of your choice, copy it to the clipboard and paste it in the application of your choosing, print it out, search for similar images on Google, share it on social networking sites, upload it to the web.

Lightshot is free software.

Take a screenshot, annotate it, and upload it to the web. You can do that and more with the free application Lightshot.