We believe that Guitar practice as an adult is more productive than it seems because it clears your head, it builds patience, discipline and concentration skills which you can transfer over to other parts of life, and it keeps your hand-eye coordination sharp. It also keeps you committed to learning and improvement, which again, are transferable traits to professional life. As role models, parents taking active classes shows kids the importance of pursuing personal interests for life.
The songs are arranged from easy beginners chords and layer up as you go thought the book. but they really work best with the website where Justin plays and teaches you how to play them then adds a few tricks and skills to advance each song too, so try watch all the songs even if you're not too interested in the song because there are gems of wisdom in them all. (I drew the line at Britney spears tho ;)
* Detune dive bomb - A.K.A. Poor man's dive bomb. On guitars with non locking string nuts, you can simulate a dive bomb by turning the tuning key of the low E string down while the note is ringing. This trick is great when used on hard tail bridge guitars with no floating tremolos. You'll have to know how to tune a guitar by ear if you intend to use this trick frequently.
Learn how to transition to different chords. One way to become proficient quickly is to learn how to transition between the various chords quickly. These transition periods are often the hardest for beginners to play when they are starting off. The more you practice between switching to different chords, however, the better you'll get at doing it in songs. Practice switching between open chords like G, A, E, and C. 
I initially bought a few books just to contribute to Justins generous cause, but didn't really think they would be needed as all this is online after all right?... but no, they have actually really helped further my skills along much faster. Just having the song book available when you get the time to play helps a lot (get the ring bound one if you can)
Though this decision can be based on preference, we think the best guitar for a beginner is the acoustic guitar. Classical guitars have a wider neck, which can be hard for younger students or physically smaller individuals to handle when learning guitar chords. Meanwhile, the electric guitar is designed to be played with an amplifier, which comes at an additional cost. Acoustic guitars are simple and require little to no additional equipment, making them ideal for beginner guitarists.