https://eve-nt.uk/designer/ - tool to render various eve ship hulls using all kinds of skins. Great for high quality cutouts and whatever you need ship images for
https://www.reddit.com/r/PropagandaPosters/ - subreddit for propaganda posters (these contain IRL propaganda images from basically every political point of view throughout history, FYI. Scroll with care.)
Corp/Alliance logos - You can find logo images for any corp or alliance you might need using either https://www.dotlan.com or https://www.evewho.com. Larger/popular corps/alliances can also be found on google.
Character Portraits - in-game, you can right-click any character portrait and select 'capture portrait.' Those captures will end up in your Documents/EVE/capture/portraits folder. Additionally, you can turn on green screen backgrounds by hitting Esc → Display and Graphics → 'Enable Greenscreen Portrait Background' - this will allow you to easily remove backgrounds from character portrait captures with image editing software.