"You need to think about how you would feel if some one took your work and claimed it as their own."
copyright is limited to "author rights" it is one aspect of Intellectual Property rights. IP rights are legislated at a global level but interpreted at a local level. copyright can only belong to a natural person and there is no requirement to use the copyright symbol on a work or to go through any legal process The convention of Berne (set up to prevent legal wrangles over rights of publishers) established that at the point of creation copyright rests with the creator.
"The pictures don't belong to you so you have to make sure you have permission to use the image that you are taking."
if you find a picture online you want to use, you must check the licence. Flickr always shows the licence information. You can use the advanced search in google images to filter for a suitably licensed image to use.