They don't need much at all, in fact the less you coddle them the better they will do. One point, pots are a hassle, they grow pretty well in the ground with nothing more than some organic compost or manure around them.

As for timing, as a light-sensitive plant, you need to understand their growth and flowering cycle.

Flowering is triggered by increasing times of darkness, ie they start preparing to flower AFTER the longest day wherever in the world u live. Here in Melbourne, the equinox is 21 Sept. Day and night of equal length - I plant seeds after that, let them grow till 21 Dec then expect them to show sex sometime soon after that. Reverse this for the Northern Hemisphere. Remember, most cannabis seedlings are killed by too much of EVERYTHING! ...fertz, water, attention etc