A real common problem new growers have is that they're not used to thoroughly dampening their soil. Often times the soil needs a good soaking before it will drain/hold water evenly throughout the entire pot. And when watering with a spray bottle you're only watering the top inch or so of soil, and the water stays there if the soil wasn't prepped properly. Its a good idea to set your containers in a tray of ph'd water and let them soak through the bottom, that way roots will reach downward to catch the water.

I know from experience that when using that miracle grow seed starting soil you should fill up a bucket with it, add water and stir the hell out of it for a while, pressing it down and squeezing the water through it, grinding up the spongey little dry clumps of soil mix. When I've used that soil I have spent probably 20 minutes mixing up a 1 gallon ice cream bucket of that stuff to get it thoroughly saturated. A friend of mine recently got a permit to grow as well and went through the same issues for 2 weeks until I came over and noticed his moisture issues. Try that out and hopefully they'll do a little bit better.