How do you show where you sourced your information from when you finish your website or is it even necessary?
I usually put a comment at the bottom showing websites I got information, pictures, etc from to give credit. I do understand there can be legal issues with some of this stuff.
It depends on what type of information. If you are using a copyrighted photo, they may have rules. But often people will credit it with a caption. Depending on the format of your site, you might have footnotes. If you’re quoting something as a block quote, a caption can work well, too.
But again, if it’s copyrighted, you may have to check if it can be used and how, including crediting.
If it’s for a simple curriculum project or demo project that is not for general release, then I wouldn’t worry about it too much.