Tutorial
As per the suggestion of a friendly viewer of this video, who said "You should make a tutorial for this.. good job man" I offer the following:
From the perspective of a beginner, the finger picking involved in "Don't Think Twice, It's Alright" makes this song incredibly complex to play. Known as "Travis Picking," the style involves both alternating and simultaneous finger and thumb motions with one hand and chord changes, hammer-ons, pull-offs and walking-baselines with the other.
The Learning Process
Preparation
Stage Zero: Travis Picking (Learn "Dust in the Wind")
Develop the structure
Stage One: Break it into pieces
Stage Two: String them together
Flesh it out
Stage Three: Introduce vocals and/or walking baselines
Travis Picking
The key to playing this song well is a mastery of Travis Picking, as the entire rest of the learning process hinges upon it. Particularly when you get to the advanced stages in which you're introducing more complex left-hand movements (for right-handed guitar players) - including hammer-ons, pull-offs, and walking baselines - you'll need to be able to focus on what your non-picking hand is doing. You won't be able to do this if you're still shaky on the Travis Picking.
Reference: http://en.wikipedia.org/wiki/Travis_picking#Travis_picking
Ironically enough, my recommendation for people new to Travis Picking is to NOT start on this song first. In the beginning the actions of your picking hand are the most significant, and the introduction of this song's fast chord changes would overly complicate the process. I therefore recommend learning "Dust in the Wind" by Kansas first for several reasons.
Reference: http://www.e-tabs.org/tab/kansas/dust_in_the_wind_(4)
Preparation: Dust in the Wind
First, the progression does not feature many complex or rapid chord changes. In fact the chord changes occur in such a way that it actually highlights the repetitive nature of the finger picking pattern in Travis Picking.
Because of this, the song can be stripped down much more easily to its constituent chord elements - C, Am, G, Dm - until such time as you've become comfortable with the basics and are ready to expand the progression to include the additional finger movements. C Cmaj7 Csus2 C / Asus2 Asus4 Am Asus2 / Csus2 C Cmaj7 in the introduction for example, can just be played C Am while you're learning.
Essentially "Dust in the Wind" provides a proper forum for the very early stages when you're just beginning to learn the right-hand pattern, and yet also accommodates the intermediate learning stages when you introduce more complex left-hand movements.
Under the assumption you have developed a proper understanding of Travis Picking, we can now move on to Don't Think Twice, It's Alright.
Don't Think Twice, It's Alright
Develop the Structure
The approach to this song is much the same as Dust in the Wind, the only difference is that the chord changes are much faster and more pronounced (e.g. it's relatively easier to move from C to Am, than G to D; and especially from G to G7). So even if you've completely mastered Dust in the Wind, you're likely to find the early stages of learning this song a bit difficult.
What I found to be particularly useful is to break the chord progression into pieces and practice each piece individually. That way you're not trying to attack the entire song as a whole, but digest it slowly.
For example the first portion of the progression is G, D, Em, C, G, D7, G, which is enough to keep you busy initially, believe me. Once seen in pieces it's just a matter of working through each piece until you're ready to start stringing them together.
This portion of the process is likely to take you a while to become comfortable with, so don't get discouraged. Finger picking in general requires a substantial time investment to develop properly, and you may find that you need to put in many practice hours before it starts to feel natural. You're training your fingers to do something very new after all; remember they need time to learn this skill.
Once you've reached this stage you've most likely played the song more times than you can remember. This is when you begin to introduce the more advanced elements.
Flesh it out: Vocals and Walking Baselines
If you're going to sing the song as well as play it I'd introduce that here, and not in the preliminary stages. This is also where you would begin to add depth to the guitar playing - including hammer-ons, pull-offs and particularly walking baselines. The reason being, up until now your complete attention will have been required to develop the basic guitar structure of the song. So introducing these additional elements prior to this point would have overly complicated the learning process.
Bear in mind that adding additional components of any kind increases the complexity of the song, which is likely to mean that you make mistakes during parts you used to play flawlessly. This is the nature of personal development in any area - you must sometimes take a step backward to take a step forward. It's normal; so it's important to be patient.
When considering fleshing out the guitar part I've found the most rewarding approach to be experimentation. I could provide the tablature for the breaks I've included in this particular video, but I think that would be to your detriment. For me, some of the most rewarding aspects of learning cover material is the process of making them your own - of adding your own personal touches or inflections to an existing work in a way that hasn't been done before. So enjoy yourself - these are the fruits of your labour.
Final Thoughts
This song can and probably will take you quite a while to learn - especially if you're a beginner to guitar in general. I chose Don't Think Twice, It's Alright as the first song I ever learned how to play, and it took me several weeks of intense practice before it even sounded like music; and several months before I began to play it fluidly from start to finish. It involves a substantial time investment - but it's worth it once you master it. Not only because it's a really fun song to play, but because Travis Picking opens the door to a wide range of additional material and adds a great deal of depth to you as a guitar player because you are no longer limited to strumming, but picking as well.
