A blog or even a website without photos are very dull and not attractive to your readers and visitors. Photos can give them ideas of what a blog or website represents. This is more crucial when your writing depends on a specific items that need readers to refer on.
Alternatively you can just grab your smartphone or camera to point and shoot. That would be sufficient. But there’s time when you do not have a specific subject to shoot.
You can just go to internet and download photos that you want. However, there are two issues that you are going to encounter when you are using free photos and graphics which are downloaded from the internet. The first one will be the quality of the photos and the other one is the copyright of the photos.
Free photos that can be used in the internet are heavily used by other people and sometimes don’t have that quality that meets your expectation. Moreover, you do not want to have same graphics and photos with other people. Some free photos are sometime quite misleading when it comes to copyright. You do not want to get sued later on.
The one that I currently use right now is FreePik.com. It offers professional free graphic resources, stock photos and vectors but if you use their resources, you have to give credit to the contributors. If you do not want to give credit, just pay 9.99EUR per month or 89.99EUR for one year. You can get access to more than 3 million graphic resources. This should be enough for your blog.
The other one that I would like to highlight here is UnSplash.com. UnSplash is an open source photo website where artist upload their photos here. The resources here can be used without having to give credit but it is highly recommended to do so in order to help the contributors gain more eposure for their hardwork. Seems fair to me.
I believe that there are more websites offer free photos and graphics for your blog. But these two websites I have been using for my works and this blog. For professional website that makes lots of return, I suggest you can look at Shutterstock.com. It is a more expensive option but I’m pretty sure that it is worth every cent you invested.