No, your plants will keep growing vegetatively as long as you leave the lights on, they won't stop. When you force flowering by reducing light hours to 12 on, 12 off, then the plants will gradually stop growing and start budding instead.
There are strains that hardly grow at all when flowering, and other strains that can easily double their height during flower... I imagine you want the first type in order to control size. What exactly those strains are I don't know for sure but if I were you I would start by researching the strains already mentioned in the previous replies, I'm sure they were recommended for a reason.
It sounds like you still have some reading to do based on the questions you're asking... find a couple of good grow FAQ's online and read the whole thing... then you will quickly find out what's most important to be successful.
And don't be too picky with the type of high, the first time around you really just want a successful grow.... and the high will be great no matter what 'cuz it was YOUR FIRST GROW :stoned:
Bulster Reviewed by Bulster on . New Grower with a few questions Hi, new grower here. I recently purchased a self contained computer case grow room. Comes with all the required gear: 250 watt red & blue spectrum light , fans/vent system, Nutrients, Self watering DWC(deep water culture) hydroponics system and pump, temperature and humidity gauge, Auto digital timers, 3 plant hydro system with netpots, growcubes, and hydroton clay rocks It's all taken care of... what may hold me back though are the dimensions of the case: Chassis Dimensions: 440mm Rating: 5