with most nutrients you just add it to the water and just water them when the soil gets a little dry on the top.
check these video's out and you'll learn alot. they're only like 30-40 min.
YouTube - Ready-Set-Grow Part 1of 7 UPDATED
YouTube - how to grow marijuana at home-part 1
this one below is alright but still kinda helpful
YouTube - How to Grow Green