The RNIB have announced that their Windows 7 and Vista Explained books for blind and partially sighted users are now available to pre-order, and will be shipped by the end of May. It's a step-by-step guide to Windows 7 and Vista from a non-visual perspective,and is specifically written to empower blind and partially sighted computer users with whatever access technology is being used.
It may be useful for you because it has been written for trainers and people supporting users with sight loss, as well as blind and partially sighted computer users.
It’s available in the following formats:
Images (sold as separate volumes)
Order a copy from the RNIB Online Shop or contact RNIB on 0303 123 9999 to place an order.
There is also an updated (and free) Microsoft Accessibility Guide for Teachers, which you may find useful
The RNIB website also gives a handy list of Accessibility Resources from Microsoft too: