The best images to use on your website or on your blog if you are writing about your business are images you have taken yourself. It only makes your business look bad when you take a stock image and manipulate it in some way and claim it as your image, representing your business or what you sell. People see this for what it is.
Taking your own photos and being in control of images you use for your business speaks to your commitment to authenticity and this speaks to what you make and sell.
If you are feeling guilty reading this, check the images you are using online.