First of all keep the light a least 4 inchs away from the top of the plant umm line your space with aluminum foil or sumthing that reflects the lighting is very important do 24 hours on for like id say a month depending and then switch to 18/6 and then 12/12 during flowering
The longer you vegg, the bigger your plant will get. Longer vegging will give more yield, but dont veg too long or you'll outgrow your closet. If you top once or twice, the plant will produce more branches and give more cola's.
This is what I do.
I'm doing SCROG in a 3x3 with 400w with 9 plants.
I veg till about 10" tall in 1qt. pots. Then transplant them to 4 gal. pots at an angle off center in the pot. Tie the top to the edge of the pot so the tips will have to grow up from there. Let it sit like that a day or to. Then top it a few nodes down from the top. Now the plant will have a root system to big for the plant mass. The plant will start growing the shoots realy fast to try and catch up to the roots. All the bottom branches take off with a bang, growing about an inch a day. This is when I put my screens in place and stick them back under the lights. In a few weeks they have the screen full and I can stick them into flower. You can see in one of the pic's how full the bottom grows in after you tie them down for a day or two. I tied them to the screen when the bottom shoots get about 12" long.
The screens are just bamboo stakes and zip ties. Held together with twisty ties from garbage sacks. Realy easy to make. Just cut them in half, tie the ends together and sip two zip ties on each side and twisty tie the two ends together in the middle. It makes a checkerboard that's 1 foot square and has about 2" holes. Tie the plant to the screen with twisty ties.
Lookin for 50g a screen this grow. I'll be updating my thread with pic's. as I go along.