First couple weeks you just want to keep the soil moist. But as they grow you'll need to water more to keep them happy. Just watch your plant for signs. Its okay to let the soil dry out its actually recommended to let it dry so you don't get mold etc.. but what I do is I water until I have run off coming out the bottom of the pots. Water slow so the soil can soak it up evenly. And my plants go almost a whole week without having to water again. I have a "dummy" pot with dry soil in it so I can compare the weight. When the plant feels light like the dummy pot its time to water
Hope I could help. Enjoy your grow