Kathy Schrock's Guide to Everything: Online Tools is a great place to start exploring possible formats and tools for your final project. While you might already have a format in mind for your resource, her list will open your eyes to lots of other possibilities that you might want to check out. Remember, part of being a metaliterate learner is to stretch and grow your abilities!
Genial.ly allows you to develop interactive, graphical information creations from infographics to guides to games and learning experiences. It provides templates to help get you started. You can view the free plan's features (click on "compare plans and features"), to determine if this will allow you to create and share the end product.
Canva for Students offers a range of templates in a variety of formats: posters, infographics and more. Be certain to select Education Infographic Templates to make sure you are using a free one.
If you are looking for graphics, videos, and other existing resources that you can share in your teaching resource, it is critical that you find content that is licensed for such purposes. Some Creative Commons licenses allow for such use. Start by exploring the types of Creative Commons licenses, to make sure you understand. There are several ways to find such content, both through the CC site and independently.
You will need to cite your sources for your infographic, to properly give credit to the authors. This guide will help you to do so.