If you use images in posters, presentations or reports you need to be sure that you attribute the image to its creator, and you might need to make sure that you are allowed to use the image. One of the ways in which you can assess this is through the license. Many images now have Creative Commons licenses, which clearly define how an image might be used. Here are some ways to find images that you can reuse:
Whether or not you have to credit the creator of the image depends on its license, although it is usually good practice to do so anyway.
If you need to design or create images, charts or infographics then there are several programs available that can support you in doing this. Here are just a few that might be particularly useful.
If you're working with images to produce or design a poster or presentation, you'll probably need image editing software. Some colleges, faculties and departments may well have access to Adobe Illustrator or InDesign (and if you've never used these, there is online training available for free here). However, if you can't, or don't want to, access those, here are some simpler alternatives that you can use for free.