Again this is another blog post; but one I am a fan of. It discusses the process of making the vital decision of creating an image with the purpose of being in colour or black and white. Picking the right image to convert to black and white can be difficult but this page gives the reader tips on getting just the right amount of contrast between the shadows and highlights without need to do this in post-editing. The post then follows this with thinking about how the image would look printed; the scale and quality needs to be taken into account. It then moves on to how the image tells a story, intentional or not. This is one important factor in deciding whether the image needs to be in colour or left without as these could impact the narrative greatly.
The next page I looked at is http://www.photographyvox.com/a/color-vs-black-and-white-photography.
This page discusses similar topics to the previous one but in the process discusses and compares the benefits and right time to use black and white or colour. I believe so far this is the best blog post I have looked at. It is brief but not too short in the sense it gets straight to the point but gives you enough material to read and think about during the photographic process.