I agree with skier31.
Instructional videos and books are great. But there's a reason to have an instructor work with you. Most of us don't actually know what we are doing half the time. We can't feel it. An instructional book or video will show you what you should be doing, but it can't show you what you are actually doing when you try to follow its instructions. You may think you're succeeding when you're way off. I speak from experience, both from the video watcher-book reader's side of the issue, and the instructor's perspective.
Our best way to know what we are doing is to have an instructor tell us, show us, and/or video us and explain what's actually going on. Then tell us how to alter it for better results, and then tell us if we are succeeding or not.
Instructors know how "blind" we can be to our own bodies. We've seen people planting their poles only on one side, right pole followed by right pole followed by right pole, while thinking they are alternating them. It's an innocent mistake, but isn't that odd? We see people thinking they are not dropping their inside hands/shoulders, when they are doing it very consistently. People do all kinds of things that they don't know they are doing, and don't do things that they think they are doing. This lack of feeling what our bodies are doing is natural -- until we develop very intense proprioceptive skills relevant to our goals. That development takes years of concentration.
An instructor with a good eye who can effectively let you know what you need to know is a great short-cut to learning.
Edited by LiquidFeet - 9/17/15 at 9:28am