You could try using Flickr...say you want to use Beautyberry for your newsletter...
Go to Flickr and search for it by its latin name (in this case, Callicarpa americana).
That will bring you to this result page...
https://www.flickr.com/search/...
Now, look at the near top left of the screen where it says 'Any license'...
click on that, there is a drop down menu...select either 'No known copyright restrictions' or 'US Government Works' for images that have no copyright restrictions, you can use those freely, without restrictions of any kind. Now, the best images probably wont be found in those 2 selections...
https://www.flickr.com/search/...
HOWEVER...if from the same drop down menu you select 'Commercial Use and Mods allowed'...
https://www.flickr.com/search/...
Now the results that come up are much better and you can use any of them as long as you credit the photographer, which will be shown clearly on the photo's page when you click on one you like...for example we'll use the first picture that comes up in this search...
https://www.flickr.com/photos/...
In this photos case, you are allowed to use it provided you clearly show credit to 'Forest and Kim Starr' along with tagging it with the same usage license. For a better understanding of what license is needed for any photo simply look to the right under the photo, just under the Taken on' date. In our examples case, you see it says 'Some rights reserved'. Click on that link and it will tell you in clear term how you may use the image and what you need to do on your end if you do.
I hope this was not overly complicated, once you are used to the way the system works, it's fairly easy to use.
Wikimedia commons is also useful in this way of finding free, usable images.
