Downloadable Photo/Video release in MS Word or PDF.
You may copy the text for use on your letterhead or write in your company on the PDF.
A release is recommended signed by all persons photographed. It is not needed when similar is signed by the employee at time of hire. A signed release is important because the employee later could claim he/she didn't grant permission to use their image. This would require not publishing images of the employee or pulling the ad campaign completely.