I have checked out Justin's site and found it to be comprehensive and informative. I have always felt that learning about music and especially music theory applied to the guitar, is helpful in finding your own unique voice on the instrument and expanding your creative horizons. Along with his insight into teaching and his fantastic abilities on the instrument, Justin has created a powerful go-to-place for anyone interested in exploring the instrument to their potential. Just don't hurt yourself.
Learn barre chords. Barre chords, or movable chords, are extremely useful for starting to play songs. In a barre chord (sometimes shortened to "bar chord"), the index finger of your fretting hand "bars" all the notes at a single fret. To play an F, which is the barre chord in first position, you bar all the notes on the first fret with your index finger and play what is essentially the shape of the E chord moved one step up the neck, with your middle, ring, and pinkie.
The simplest answer and the one that no student that ever wants to hear is practice. Changing chords is the process where many beginners fail, and quit. But after that, the rewards will be simply impressive. There are a few tricks to get a chord transition to happen faster. Use a metronome: Set it on four beats and set it as fast or as slow as you want. Then get a chord in your mind, say D. When the metronome reaches its last beat, press down the strings. When it happens again, strum it and let it free. Then again. Do this 10 to 20 minutes a day and in less than a week, the chord progression will begin to sound much better.
3/4 Size Acoustic: I also have a 3/4 Scale Guitar in my apartment because they are awesome to sit beside your couch and just pick up easily and jam with. I bought the guitar a few months ago, and when I was playing it a concerned shopper came up to me and reminded me “that’s for kids you know.” I laughed. Fair enough, but I think little guitars are cool to have around the house, so if you do too (or if you have really small hands) perhaps this could be the guitar for you.