Looking good so far, congrats. Yes, you should be ready to harvest in 5-6 weeks. You'll know it's time when all the fan leaves have yellowed and died off and the bud leaves are yellowing. A pretty good flowering nutrient that you can get at Lowes is Better-Gro Orchid Bloom Booster. Feed it at a rate of 1/2 teaspoon per gallon of water at every feeding.
Also, moved your thread to the New Growers Forum.