Welcome to the wonderful world of fly casting, were you will learn to swear, get hooked, snagged and totally frustrated. But after you master the basics of casting and then get your first trout to rise to a fly and then you catch your first rainbow or brookie or brown, you will be with us forever. I have been trying to master this art for over 60 years and still wonder if I will ever get it. But I have more fun, become more relaxed and more in tune with nature than anything I have ever else attempted.
Get Joan Wulff's Dynamics of Fly Casting in VHS or DVD. Learn her lessons and practice, practice, practice.
You will receive so many different answers to your post that you will feel overwhelmed. Practice, practice, practice.