There are not so many original ideas these days.
Many of the things we think about, were thought before. Many of the things we write about, were written about before.
When we are asked to research something, there are SO MANY places we can get information from.
Strong researchers use books, databases, websites, primary resources and anecdotal evidence to learn.
Whenever we read information, there are some parts of it that stay with us, and some parts we forget. It is good to take notes while we are reading, so that we can remember the important parts. We might not use all of this information in our final product, but if we do, it is important to know where that information came from. Sometimes we use the information in the exact way we found it, where we might quote exactly what was said, and some times we might paraphrase the ideas we discovered. No matter what, we have to cite where it came from.
We have to cite our sources.