Handcuffing a Designer?

As I am preparing my instructions for my designer I was just wondering how much info it too much? I really have a tendency to want to tell them how I want every thing done like color, what pics I want to use, location of the pics, how I want my flash to work, how I want the title, and about every single detail I can possibly think of. Do you think this is the right way to go or should I give them more freedom to create what they think is best? “keep in mind I am familiar with PhotoShop and design myself” :construct