It depends. Being able to access an image for free on the internet, for example on Google, doesn’t mean you are allowed to use it in your own resources. Many online images cannot be used without obtaining the prior consent of their owner due to copyright protection.
You must ensure that you have the right to use any images in your own resources. It is always safer to use images / photographs / designs that you have created yourself, although this may not always be practical.
The websites below which contain images you may be able to use in your resources but before incorporating any image from a website into your resources, make sure that you read and understand the licence terms and conditions under which the images are offered.
Subscription based / pay per image
The information contained on this website is for general guidance only and should not be relied upon as legal advice.