I need help. I took golf lessons, that basically helped me with the fundamentals. Before the lessons, I could hit my long irons and not my short irons. NOW, I can not hit my long irons and very inconsistent with my short irons. However, my putting has improved considerably and off the tee!!!

I have been told my posture is good, grip is good, my follow through is good...but I am not able to hit with my irons. Where should the ball position be when hitting long irons? A what does it really mean to keep the clubface square? How can I tell if it is square to the target?

HELP!!!