Should I let a co-worker know im interested in dating him?

Ok, quick question. I'm a teacher, and recently there was a new addition to our staff. He is our Dean of discpline and I have a growing attraction towards him. We've conversed regarding our students, and other general topics. He did hint that he was single with no children, and I could have swore that I saw him checking me out on a few occasions. My question is this: Should I make an advance? There's a few issues I can see with this scenario: A: Would it look a lil aggressive if I come on to him? U know, me being a woman and all, I don't want to seem intimidating or desperate (I know it's 2009, but I'm still a bit traditional when it comes to dating). And B: If by chance he's not interested, would I create an uncomfortable work envrionment? I dont' know what to do!! So please, someone who's been in this situation (good or bad) please share with me your experience and advice. Lastly, if you are in favor of me making the advance, what should be my approach?

Signed,
Silly Girl.