With sufficient determination and discipline you can teach yourself to play the guitar. But there are a number of pitfalls you need to be aware of if you are trying to learn from books and online courses. 

Method books promise answers, but they don’t teach you real songs. They can teach theory, and technique exercises, but they will only have etudes “in the style of” your favorite artists. They may also contain song fragments, or "licks." Even the large publishing company that owns the copyrights to artist approved notation will publish versions of songs that don’t match any recorded version. You will spend your time learning a song that will sound quite wrong when you try to play along. Sometimes all you will need to do is transpose up or down one step, but often the chords and techniques are substantially different. 

Online courses have much the same problem. Plus you have to sift through all the click-bait courses to find any that have real value. The “one shape” that “unlocks” the entire fretboard? The “interlocking pattern” system that will instantly let you solo like your guitar heroes? Give me a break! Scales are important, but they’re not some hidden secret, and running scales won’t make you a great player.    

These books and courses contain useful information, but music theory and chord dictionaries won’t stick unless you are applying these ideas in real songs. 

Of course, there are also songbooks and online transcriptions. These are frequently simplified or just inaccurate. If the publisher claims to sell the “recorded version” or “artist approved” transcriptions, you can generally expect the songs to be accurate. The difficulty is that artist songbooks are not arranged to progress from absolute beginner through intermediate and advanced. Basic and advanced techniques sit side by side in any given song. 

The true “secret” to accelerated learning is to learn real songs that progressively teach the principles of music in a logical and systematic way. This is something a good music teacher should do, and something we strive to provide our guitar students at Martin Music Academy.