So, Pinterest is the equivalent of making a scrapbook. You create 'Boards' which are themed in some way and 'pin' relevant things to them. They can be public or secret.
For each of my books, I made separate boards. These are public. I then used the Search option within Pinterest to find scenes which fitted scenes in my books. I typed in words such as 'snow', 'treasure', 'miniature', 'castle', 'witch', etc, etc.
When you find something you want to keep, you just click on it and an option comes up asking which board you'd like to save that image to. You can also pin written information such as articles, blog posts, publications, etc.
You can also pin things when you're not even on the Pinterest website. Just look for the red 'P' wherever you are on the Internet. Once you click it, you are asked if you'd like to pin it, and on which board.
You can follow people and can be followed. I don't really get involved in that side of things!
I still add things occasionally, although I am pleased with what I've got as the board for each book gives quite an authentic pictorial representation of what the books are about.
Here is my page where you can see what I've done:https://www.pinterest.co.uk/helen_laycock/
My private boards consist of private collections of ideas for the house, etc.