If your planting them in the ground I'd wait til they had at least 3-4 sets of leaves so the slugs are fatal. If your using buckets do it now. As far as smell goes, while in veg the smell is minimal, which means you gotta be right up on them to smell her. Once flowering begins it's a whole other story, it could smell quite a distance away or not at all. It all depends on the strain your going with.