The employer I currently work for does not provide any tuition assistance. I was wondering, if my employer paid for me to go to Graduate School would they be able to write off all of the expenses on their corporate taxes (we are a company of approx. 70)? If the company pays my tuition and books what costs do they actually incur?

The company would be able to deduct your costs of graduate school. The costs would be treated as income to you (and reported on your Form W-2) and the company would have a deduction for compensation to you.