Diesel is right, but sets of higher reps are also important though. Heavier weights will build more net muscle, but high reps will build more muscle in a shorter period (the first will add a good trade of fiber and mass, the second mostly mass, which grows much faster), so make sure you have both in your routine. The westside barbell template uses sets of up to 15 in all the "extra" work (shoulders, back, arms, chest, etc), they only realy do very low reps for the ME and DE lifts.
As far a mind-muscle goes, it'll come with time (your muscles become better innerved and you'll gradualy gain this ability, the average joe can't bounce his pecs, but one quickly gains this ability when starting weightlifting

), don't worry much with it for now.