Nutrient schedules are something youwill flavour to, we all end up with our own flavour (List) of nutrients we like to use once we get experience.

I know that you can use nutrients at the early stages of seedling and or cloning. Here are two products that support this:

Aminozym (By Crop) can be used with seedlings and clones to stimulate root growth, here's a snippet from the directions, "1. Use from the start, until end of 2nd week into bloom, soaking grow cubes for cuttings etc..."

B52 (By Advanced Nutrients) Can be use from seedling and clones also (As well as using on the leave as folior spray on clones/seedlings). Here's a snippet from the bottle, "Apply B52 at rate 1ml - 2ml per 1ltr of Nutrient Solution throughout all plant growth

Nutrients are designed for various aspect of the plants growth, there are basic nutriets that a plant must have and it will be a personal flavour as to the list of nutrients will will end up using.

Rule of Thumb: Always follow instructions on the lables as a base guide, then once you have confidence with your knowledge of nutrients, you can start being more agressive with your nutrients etc...

Hope this helps a little...

Cheer!