Seeds
If you want some killer pot you have to start out with killer seeds. You will want to do a little research before you pick out the strain you are going to grow. Some strains like outdoors and lots of light and some like indoors under lower light conditions. I like indoors because you can control the plants environment. Plus you don't have to worry about pest and critters eating your plants. Well not totally but your chances are better than the open outdoors.
The seed is where it all begins. You cant just take any old pot seed and expect it to grow bad ass weed. Its all in the genetics. To grow bad ass weed you have to have bad ass seeds.
I hear these are some good places to buy seeds...
http://www.rollitup.org/seed-strain-reviews/1288-marijuana-seeds.html