Looks like you have a way to go...til 3/4 of hairs go red and look at the colas under a hand microscope and check the color of the resin...clear? cloudy? amber?...go for the cloudy or amber.
You got anywhere from 3 to 5 weeks left. Look for trichomes, you will have to buy a cheap magnifyer because they are not visible to the naked eye but the trichomes will be mushroom shaped when the plant is ready to harvest. Congrats man that looks like its going to be some good ass smoke.