hi smallgrow,
I stated to flower at 21 days and they werent that big, now there about 2 feet tall as they had a growth spurt when i started flowering, so id suggest 21 days for veg then flower. What light are you using ? This is my first proper grow aswell, its good fun but remember not to tell anyone and leave any paper trails !! keep me updated with your progess etc

Charbud