The old traditional method of learning Piano was through a Piano teacher and it was very costly. Students can now learn Piano online or with tutorial videos. If needs, they occasionally get instructions from a real Piano teacher.
It is however, better for a new student who will be touching the Piano for the first time to learn the traditional way for a few months, as a good teacher can monitor your progress and correct the mistakes if any then and there.
You can be your own teacher and sometimes, you may need extra practice. You can learn from home at your own convenience. If you feel boring, you can give a break. Even if it takes time to master the instrument, you should not lose heart and give up.
It is important to master basics first. They are learning the notes, rythms, chords and so on. There are step by step lessons which will guide you with proper details and enough information how to play. By playing them same thing over and over again, you may feel dull and boring. So you can practice different kinds of songs and even change to different techniques to get motivation.
A good Piano course will guide you to become professional Piaonist. Due to technological development, it is now possible that you can be your own teacher and become an expert player without resorting to the old traditional way of learning. But what you require is that you have to be focused, positive and motivated.
There are online tutorials to try and begin the course but it will be incomplete. You can buy online lessons and DVDs to continue the learning. It is important that you should choose the right lessons for you.