The steps to make sure you get THC:
1.) Make sure you get a good strain to start with
2.) Make sure you're growing a female plant
3.) Take care of her and give her enough light (this forum is all about caring for cannabis)
4.) Make sure you harvest the buds at the right time (there's also tons of info about that)
So, the first step is obtaining a good strain either as seeds or a clone, then start reading up on cannabis care. Feel free to check out the Basics section of my website, GrowWeedEasy.com, if you're looking for a simple guide that explains what you need to do to grow a happy, healthy cannabis plant.