There’s no single way to learn how to play the guitar. To some people it comes naturally and they may not need much instruction at all. Other people may have to practice until their fingers bleed. Some people need a structured environment such as a classroom setting and others may need one on one instruction with a teacher every week.
I was never good with structured settings. I preferred learning from books or videos. I liked to work at my own pace and pick and choose my lessons as I went along. Some instructional purists will tell you this is absolutely not the best way to learn to play guitar, but it’s worked for me for decades.
The point is, nobody can tell you which way is the best way to learn anything. Deciding how to learn guitar is a choice you’ll make based on what you know about how you absorb and process information. I like DVD guitar courses because I can choose the things I want to learn, I can watch the lessons any time I want, and I can always refer back to a lesson if I don’t get it the first time.
You may decide a combination of methods work best for you. There’s nothing wrong with working with a guitar teacher when you first get started, at least to get the basics while you’ve got someone to hold you accountable, and then branching off on your own when you’ve gotten just enough information to be dangerous.
If you’ve never picked up a guitar in your life, you need to at least get familiar with the basics, such as how to tune and how to put new strings on. You should learn basic open position chords and apply that knowledge in a real world situation by learning to play actual songs. Beyond that, there’s nothing magical that tells you how to learn guitar. It should come organically, through experimentation and by listening to, and trying to replicate, some of your favorite guitar players. That’s the real key to how to learn guitar.