The easiest way to avoid plagiarism is to learn what you are reading and then convey it in your own words. You are not considered a copy-paster if you are providing information that you have got from somewhere as long as it's in your wording and you are not writing it in the same manner you read it. This is what I do to avoid plagiarism and to be able to populate your posts with essential information, news, and any other thing that might have some weight.

If you think you can't do that or you don't want to do that, then as suggested by others, you will need to give a reference to the source from where you have copied the information, and if you don't do that and someone catches you, you risk getting your account ban or at least get a negative trust rating.