Watering- Enough to saturate the medium but only when dry (To test if dry poke your finger into the soil about an 1"-2", if dry you can water. Second way of telling if dry is by lifting your pot as if its full it will be heavier than when dry.. test both so you know when its dry.
In terms of nutrients, use 1/2 the recommended dose of the nutrient line you use, and in some cases 1/4 strength then work your way up little by little. The first 4 weeks you shouldn't need to use any nutrients as your growing in soil which already has enough nutrients in to last you the first 4-5 weeks, some cases, 6. You'll know as your plant will show signs of deficiencies if it neeeds nutrients, then would be the best time to act upon using them as you don't want to over feed with nutrients and get nutrient burn which will slow down your growing process. Thats just a short answer, any help required.. drop me a message. Hope this helps.