Self Help Guides produced by Northumberland, Tyne and Wear NHS Foundation Trust https://web.ntw.nhs.uk/selfhelp/  Titles cover a range of mental health issues.

Living Life to the Full provide lots of different online self-help courses that are highly recommended by mental health professionals, covering lots of different specific topics and groups, including helping you to tackle anxiety. 

Moodgym is another online self-help program designed to help you prevent and manage symptoms of depression/anxiety. It's like an interactive, online self-help book which teaches skills based on cognitive behavioural therapy.