There are threads about fimming, topping, and LST in the FAQ's here: Grow FAQs - Cannabis Forums Message Boards - Medical Marijuana, Cannabis Club, Dispensary, News

I'd get some nutrients made for specifically for cannabis. If you can't, then try to match the N-P-K ratios with what you decide to buy. For example, my Canna soil nutrients are Canna Terra Vega 3-1-4 (for veg) , Canna Terra Flores 2-2-4 (for bloom).