How old is he? Around a year old, roosters go into the "teenage boy" phase. He needs to know that YOU are at the top of the pecking order, not him. I have a "rooster stick" I used to use on my aggressive RIR rooster. He finally had to go. He got horrible. But, when he would come at me, I would pop him with the stick..just hard enought that he got the point.. not hard enought to actually cause damage. Also, don't ever walk around your roo.. if you walk into the coop and he is in your way, MAKE HIM MOVE! By doing that, you are showing him that you are the dominant one. Not him. Do not ever let him breed a hen infront of you. When he does this, he is trying to show his dominance. Knock him off of her.
Like I said, my RIR rooster finally had to go. He got so mean that my inside dog couldnt even go outside.. he would spot her across the yard (6 acres) and take off in a full sprint just to attack her.
I have a Wyandotte rooster that is wonderful...he has NEVER tried to attack me or even looked at me cross ways. He does what a rooster should.. he protects his girls. He isn't aggressive toward them either.