Suggestions in the guide include closing windows and doors to keep heat in an office, using energy efficient lighting and switching off electrical equipment which is not in use.
The Carbon Trust has estimated that one computer and monitor left on for 24 hours can cost a business about £50 in electricity.
Hugh Jones, the solution's director of the body, said the guide will help charities to make effective use of their resources.
The expert added: "This will not only lead to savings on energy bills but will also demonstrate an organisation's environmental credentials, which could attract future benefactors."
Set up the government, the Carbon Trust helps to encourage organisations in the UK to become more energy efficient.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.