There is a brand new updated version of this article here: How to find copyright free images with Google and other resources. The general rule of thumb in the Internet world is that at least one image should be used to complement every blog post you create.
Facebook. Twitter. Pinterest. Stumbleupon. Whatsapp. Email. Advertisement. How often do you use Google Image Search? Or do you bypass the image search for the “always in your face” Google Web search?