This two-part series shares some great practical advice on cameras, lenses and image quality. It's worth a read.
Here are a few quotes that resonated with me:
"We often think of image quality as a technical thing but no amount of high end cameras lenses and equipment can make up for poor composition and lighting. No matter how sharp a picture is or how many pixels it has, the biggest factor in image quality will always be the photographer."
"The camera is the least important part of the capture process except for specialist subjects like sport. It is impossible to tell what type or make of camera was used for any of these pictures. However the quality and characteristics of the lens is written in every image it creates."
"Generally speaking, buy the best lenses you can afford. Typically an $800 lens on a $300 camera will produce better photographs than a $300 lens on a $800 camera."
"IS or VR does not reduce subject movement and is no replacement for a large aperture when shooting moving subjects like people. Using a fast standard prime lens at f/2 with a corresponding shutter speed of 1/125th second is likely to produce a better quality portrait than using a regular standard zoom lens with image stabilisation wide open at f/4 with a shutter speed of 1/30th second."