Suppose I'm setting up a website, and there are loads of images. These images won't change. But I would like that when any members of the team clone the project, they get the images so that they run the website immediately. Does this mean that I should add track the images as well? I'm just taking an example, it could be a jar in a java project or something else.
Yes, absolutely. Track any file you need. Git is more than happy to let you track non-source code files.
If you need something really big, you can also consider git annex. That versions which files are needed in git, but the files themselves are fetched separately, so their history does not take up space in everybody's repository.