CFL: compact flourescent lighting
24/7: 24 hrs a day 7 days a week
18/6: a common light cycle for veg. growth 18hrs on 6 off
12/12: the change in light cycle to trigger flower production in cannabis 12 on 12 off
Leaving them by the window is not enough you need to have a room with no light leaks
an interruption in the light cycle while in 12/12 will interrupt bud production.
Please read the grow faq. There are alot of things to learn and this is a great place to learn them.
Good luck!