- Provide references unless your point is seen as 'common knowledge'
- Some areas of knowledge are contested
- Ensure you cite supporting literature
Something which a lot of people get confused about is deciding when they do or don't need to reference something. Ask yourself – 'is this common knowledge or not?', and be aware that again this will vary from discipline to discipline.
In every field there will be things which you can take for granted: criminal trials take place in court; mixing copper and tin gives you bronze; most people have two legs. There will be some statements which aren't quite as black and white as this. If in doubt, it's always better to support your claims than not.
Some areas of research are contested and it is important to be aware of and acknowledge other schools of thought if they don't necessarily agree with your point of view. Not only should you come up with references which support your own point of view, but you also have to show that you recognise that there was a different opinion: you'd need to provide references for people who disagreed, and show the evidence for why you disagree with them.
You can't ever do too much background reading, but you can do too little, so references to plenty of supporting literature won't go amiss. The way in which you reference will depend on your discipline and the style guide of the publication you are submitting to, but as a general rule of thumb, being over-precise is better than too vague. The reason you are referencing is so that people who read your article can see where you have taken that quote or idea from, so make it as easy as possible for them to find the original.
A good habit to get into is making a list of your references as you go along, so that you don't have to go back and look for things after you've finished, which is when you can make mistakes and end up plagiarising something unintentionally.
As a minimum, you should list any work to which you have made reference, but it's also good practice to list anything which you haven't specifically mentioned, but which shaped your thinking for the article. You don't have to include everything you've ever read – try to find a balance so that you include anything you think is relevant.
Finally, plagiarism is stealing someone else's ideas, whether done intentionally or not. Clearly, you need to reference any direct quote. But you also need to reference if you base any part of your article on someone else's concepts or ideas.