It is very helpful to have clear role descriptions for your trustees, with specific descriptions for officers so that they know what it it that you are expecting from them.
These documents are draft examples only and come with the health warning that you should adapt them to suit your organisation and not simply copy and paste them.
Useful Documents
Sample Chair of Trustees Role Description
Sample Treasurer Role Description
Sample Honorary Secretary Role Description
Sample Role of the Company Secretary - this is required for organisations that are also Companies Limited by Guarantee