Annual reports should not been seen as an administrative task that needs doing each year. They are an opportunity to show of the difference your organisations has made in the year, as well as to thank your supporters and volunteers.

As you have to produce the report, it is worth investing a bit of extra time to make something that shows your work of to the maximum.

This is a good guide to set you off in the right direction
http://www.philanthropycapital.org/publications/improving_the_sector/improving_charities/talking_about_results.aspx