One VERY easy way to find pictures, illustrations, icons, graphics... that can be posted with no royalty fees, mostly only with attribution rights (meaning, just annotating the source and the CC license) is making a search within Word or PowerPoint.
To do that, just go to the Insert menu on top. Select "Online images". In the box that opens, just write the term you are searching for (nature, women, business...). Then, select "Only Creative Commons" in the license options in the top menu (do NOT select "All" as this option will display many more images, but most will not have a royalty-free license).
Once selected, just click on the "Insert" button at the bottom right corner. The program will insert not only the picture, but also the corresponding attribution text with the links to the source and the CC. Great!
For instance, I just made a search in PowerPoint for a "search" image and found this one (among many, many others; ones more useful than others of course):
Esta foto (fuente) de autor desconocido está bajo licencia CC BY-SA
RE: Don't Plagiarize Images! Here are 13 free (and Legal) ways to find high quality photos you can use on Steemit.