Reddit mentions of Alfred's Self-Teaching Adult Piano Course: The new, easy and fun way to teach yourself to play, Book & Online Audio

There is a whole set of lessons online here that would probably be perfect for you:

• http://www.howtoplaypiano.ca/?page_id=67 (his Youtube page is: http://www.youtube.com/user/Lypur)
  
  Also checkout the links and discussions under "Getting Started as a Beginner" in the sidebar -------->.
  
  Although we don't have too many online resources like the one above. See the other information and links in the FAQ too.
  
  You could also get a book like this:
  http://www.amazon.com/Alfreds-Self-Teaching-Adult-Piano-Course/dp/0739052055/ref=sr_1_3?ie=UTF8&qid=1342832792&sr=8-3&keywords=teach+yourself+piano
  
  Ideally you could eventually pursuade your parents to pay for lessons or you could get a job and pay for it yourself haha. One of the keys to learning to do any activity is having someone who can guide you, give you feedback, answer questions, etc.

Oh man, entertainment can be had for relatively pennies my friend.

Check this book out, and look for an inexpensive or second-hand upright piano (ideally a pre-owned or cheap and new keyboard to start, pianos are expensive and need tuning), and go at it. In a year you'll be able to play many simple to intermediate pieces and you'll be able to impress a lot of people and add a very therapeutic practice to your life. Music does a lot for ones attitude and outlook on life.

Don't think you can do it? Ask me any questions because I did exactly this, with the same book, and now my path has lead me into making some of my own electronic music.

It's doable friend. You just need to be patient, persistent and spend a half hour to an hour (even 15-20 mins works) a day tuning out all the distractions in your life and focus on building a new part of your personality. You can do it. That book so easy and simple to understand I bet money anyone could learn.

Guitar is great too. There's no need to invest in a fancy piece, there are plenty of people who started off with an inexpensive guitar or piano and want to part ways with it. Look on Craigslist or your local for sale boards. You'll find some beauty looking for a new student.

Good luck with it! And most importantly, don't do it for the likes or impressing others. Do it for your own personal growth. Witnessing change in your own self is one of the most amazing parts of our short but sweet existence. Give it a shot, you don't have anything to lose but a few dollars and time, but the return you get will pay off in countless ways it's a no brainer!!

https://www.amazon.com/gp/aw/d/0739052055/ref=mp_s_a_1_7?ie=UTF8&qid=1482584630&sr=8-7&pi=AC_SX236_SY340_QL65&keywords=alfred+piano&dpPl=1&dpID=51PASYE3aXL&ref=plSrch

Do note, this is coming from someone that took lessons since I was young and went through courses to be a music educator in college so I may not have the most relatable experience, but here's my take.

I say it depends on the kinds of music you want to learn and play that will influence on what you should be focusing on.

There are beginner books for adults available such as this one that will go through beginning concepts at a much quicker pace than what I went through as a child. A lot of my music friends used something similar (can't find the one they used, sorry) to pass a piano proficiency exam. They did have a professor coach them through, which streamlined the process.

I'd suggest going this route (teacher + adult beginner book) as it will give you the best foundation that can be branched off into whatever interest you have. You'll learn a lot of fundamentals such as proper posture and reading sheet music and you'll do it at a much faster pace than if you were younger.

There are other alternatives too. I had a dorm mate from Costo Rico that just wanted to learn how to jam on the piano when his buddies whips out their classical guitars. So I spent an evening teaching him how scales are formed and how major/minor chords are formed. After a couple weeks of practicing and asking a few questions during that time, he got to the point where he could jam with his buddies. He couldn't read sheet music, but if we tell him what chord and scale, he'd figure out what sounded all right and jam along. He could also look at chords online of simple songs and he'd be able to figure out an arrangement on the piano he could manage within a week.

Hope this helps a bit in your decision :)

If you can't get a teacher, then try a method book. There is one developed for adults by Alfred that you can find on Amazon. Using something structured will really pay dividends for you as getting your left hand to work is one of the first challenges of being a (right handed) pianist. Even as a child, I remember struggling initially with my left hand and all these years later my RH is definitely more dextrous than my LH. You'll need to initially spend maybe 4 times the time practicing your LH then you spend on your RH for the same section. In time though, you brain will get used to guiding your LH. Also, psychologically, try not to think of this as 'hand independence' - you don't want your hands to be independent, you want them to collaborate together to produce a single piece of music. Goo luck

If you are thinking about that book, (which I do like, and used with many of my adult students) - I'd suggest getting this instead. It's exactly the same book but the left hand pages contain advice on things a piano teacher would be looking out for if you had one. It's not the same as actual lessons, but it's a big improvement over just guessing.