This website is a goldmine of information and practical advice for the third sector! If you do not already know it put it on your reading list and ensure you take a look.
"Evaluation can help you to work out what difference you are making through your services or activities. Evaluation Support Guide 1.1 helps you to clarify your aims, outcomes and activities and Support Guide 2.1 helps you to use indicators to measure your progress.
This guide shows how case studies can help to bring your work alive.
They can help funders to see that their funding is having a positive effect. They can also show potential service users how your project could benefit them. However, it is not always easy to write a good case study! This guide offers some ideas."