Sooo.....

How long after the white hairs emerge does it take for buds to start growing.

Do the buds grow right where the hairs are?

I like to divide flowering into two phases. Stretching followed by budding.

At the start of budding, as the stretching slows, you will see clusters of white pistils appear here and there. When the growing tips stop producing leaves and turn into white snowballs with just tiny bud leaves then she is in full flowering mode and buds will start appearing rapidly all over the plant. From there it's about six weeks to finish depending on the strain and the conditions.