Your priority should always be to find the best quality instruction available to you. This can be the deciding factor as to how easy you find it to learn, and consequently how likely it is that you will succeed. I dont recommend self instruction, as this often leads to frustration in the future, and frustration makes it more likely that you will just give up.
My best recommendation is to find a good local tutor, although this is not always possible. Failing that, there are some great online sites to learn to play acoustic guitar, but choose wisely, and be sure to try out their sample lessons first. You need to make sure that the pace at which they teach, the style of their teaching, and the level of the lessons are suitable for you.
The ideal situation is to have a combination of strategies, where you learn from a variety of different sources at the same time. For example, one on one lessons with a real tutor, plus online guitar lessons, or books and DVDs. You'll definitely need to be self motivated and committed to daily practice, which unfortunately, not everyone is! But assuming you possess some kind of inspiration that is driving you to learn acoustic guitar, everything should be fine!
One of the most popular questions asked by beginners is, how long does it take to learn? I would say that normally its around 4 weeks before you can strum along to basic beginner songs. This assumes you're being taught a good quality method for guitar and possess an average aptitude for the instrument. Beyond that however is a never ending journey which youll probably never reach the end of - no one ever does! Life is a learning journey, and playing the guitar is no exception.
Aside from quality guitar lessons, the most important strategy will be in knowing how to practice correctly. Practicing is a technique you have to learn! I've seen many a student frustrated because they have practiced and practiced, but have been using the wrong technique. So in effect, their practice has been in vain, because they then need to unlearn what they've been doing, and re-learn the correct way. Learning how to practice correctly will shorten the time it takes you to learn to play acoustic guitar enormously, it may even mean the difference between success and failure.
