The most important thing to know is how competent and trustworthy your subs are. You can't be expected to know everything about every detail and wherever there are gaps in your knowledge you need to know that you can rely upon your subcontractors. I consider myself pretty well-versed in a wide range of construction knowledge- I always say that I'm a better plumber than my electrician and a better electrician than my framer- but I work with masons and electricians and framers and roofers and I am appreciative and in awe of their specialized skills and knowledge and if you're lucky enough to have subs like that than you don't need to toss and turn at night worrying about the little details that are second nature to them.