Writing in your own words
All the information, quotes and examples you use in your assignments must be properly referenced, partly to help your reader find the material if they need to and partly to protect yourself from any accusation of plagiarism. So, whether you quote a person directly or merely mention their work, you must ensure you acknowledge them by referencing your sources.
The Referencing and plagiarism page of the Library website contains useful information and guidance about referencing styles used at the OU and guidance is also available on Bibliographic management.
Referencing practices do vary between academic disciplines and modules so it's a good idea to check your Assignment Handbook for information on what style of referencing is preferred.
It's also a good idea to use a number of different sources in your writing.