So don't go using an image like this and thinking you created it in your marketing. Major no no. Trademarks aren't hard to find and sometimes you can even ask for permission to use something and it's no big deal. You might stumble upon a JV deal or affiliate product you want to add to your marketing. When you do catalogs online or offline, ask for the imagines directly from your vendor.
Even when you do JV deals, promote a book or a product from someone else, just ask for the images you can use. That's easy to do. People are Asia Email List happy to provide them and respect the integrity it takes to ask. The legalities of copy writing and writing ad copy is pretty significant. I surely don't want you to turn into a paranoid writer but be mindful of these rules. You can get a good overview of what they are here from The American Writers And Artists Inc.
This book shares what you can and can't say in copy and how to be wise. If you aren't looking to make 6-7 figures AS a copywriter I don't think you need this book. However, if you are selling weight loss for example you might find it important to note that in this book you'll see that outrageous claims, misuse of testimonials and stating things that can't be scientifically proven could fry your butt in the long run.