ICO: Privacy notices under the EU General Data Protection Regulation

Somewhat older: ICO, Privacy notices, transparency and control - A code of practice on communicating privacy information to individuals, 7 October 2016
[...] This code of practice is designed as a good practice document to help you collect and use personal information fairly and transparently and give individuals appropriate control and choice over their data, including in a digital context. It focuses on drafting and communicating clear privacy notices that ensure that individuals know how information about them will be used, and that they understand the impact it will have on them. [...]

And another one: Overview of the General Data Protection Regulation (GDPR), 13 October 2016