I take no credit for this material.
Grouped here is the official briefing material from Combat Mission Battle for Normandy, and the Commonwealth Forces and Market Garden modules. These were originally available on the Battlefront Repository, however appear not to have been transferred over to the new CMMODS.
All files are in .psd format and will require photoshop or a similar program to access. The open source Paint.net program with the .psd plugin is also an option for budding scenario makers.