I hear quiet a bit of chatter about guitarists learning things by watching instructional videos on You Tube. Let's face it - You Tube is full of amazing information and many guitar instructors strut their stuff all over the net. Heck, even my "Metal For Life" instructional videos have been seen by close to 4 million people.

It can be fun watching a snippet of a new guitar idea and then taking it even further or taking the challenge of learning something new note per note. 

There is one ceveat.  That is a lack of a bigger plan and constructive feedback.

It is hard to get amazing on the guitar by jumping from one video to another.

A student is unaware of what he or she doesn't yet know. This is not always the case, but often is. Students will also spend a lot more time watching videos on the things they like and less on videos that focus on their weaknesses.

So, although it is certainly helpful and indeed possible to get very good on your instrument by watching You Tube lessons - you can speed up the process quiet a bit by studying with an experienced teacher who can present you with a program or a plan to help you build all aspects of your playing.

A good teacher will also give you extremely valuable feedback on your playing. It is sometimes very difficult to be objective about your playing simply because you are too inside of it. It is hard to step back, be honest and hear yourself with a "different" set of ears. This is what great teachers are for.

So, if I had to give some advice for best and fastest results - I'd recommend both. Learn all you can from You Tube and find a great guitar teacher that is truly interested in teaching you.