First question i have is how much water should i give my plants? and how often should i give them water?.
You should water your plants whenever the soil seems to feel dry about an inch down in the dirt...I usually stick my finger a good bit down in the soil to see if it still feels wet. When I water them I usually just give them enough to where as it gets a good runoff started and then I let it drain for like 45 min before putting back in my grow room. If you look at my first grow in my log I used my tub to water and drain my ladies and it worked out well for me!

My other problem is these tiny black flies that seem to be attracted to the wet soil and water.
And to answer the black flies question....From what I know the flies come from the soil already when you buy it...They are eggs and when watered by the grower they hatch because of the water and light, somewhat like a mosquito in water! Not sure really what you can do to control it other than cover the soil with some type of plastic or something to keep the light from hatching the eggs, but I find the little fu**ers are more annoying than anything, so I just use hand-to-hand combat to get rid of those little suckers!:stoned: