Things to consider:
Images are important to visual story telling. Will most of the images have need to be taken by a photographer? Will you be providing them? Will we need to use stock images?
Who will be providing the copy for the project? Will if be someone on your staff, an independent copywriter or your design team? Keep in mind most designers are not writers, nor can they fully grasp the details of your services or products without some feedback from your organization.
You should be able to provide feedback to your designer about who the intended consumer of the project is. Are they old? Youn? Female? Etc.
Do you have an idea in mind on the type of medium you will be using and the potential size? (ex: tri-fold, banner, ebook)?
When do you desire for your project to be completed?