You can start on your own and later get formal instructions of various harmonica masters. If you stick up to my advice, you'll get what's really valuable - your own ideas and understanding of the instrument.

I decided to learn to play the harmonica about seven years ago and most of the time I was experimenting on my own, though I admit to having used some formal instructions from time to time, too.  

As the harmonica is laid out in an intuitive way, learning how to play the harmonica by yourself is not a difficult task and it's worth trying. You can purchase a harmonica with a small introductory packet explaining the layout enclosed in the box.

What is important to know is that everything is already set up in the chords. You need to play most kinds of music on a richter, or ten hole diatonic, harp, which gives you the opportunity to pick out basic melodies as soon as you try playing the harmonica for the first time.

Having the basic knowledge, you can easily improve your skills by regularly practicing playing this beautiful instrument. If you have already learned the basics, harmonica play by the numbers, then you might consider getting some professional help.

Of course you can start taking harmonica lessons by a teacher or you can simply start listening to harmonica music played by other musicians. Music is said to be the best teacher, so why don't you gibe the second option a try.

In case you do so, you will get many new ideas and in addition to that playing the harmonica might enable you to give your own musical expressions which will be added up to your repertoire.

If you choose to get a harmonica teacher verify that they are experts in playing the exact same style that you want. For instance, imagine you learned how to play the harmonica in the Chicago bells mode, then you would not be able to play bluegrass or country blues harp as they all are very different styles.