Reddit mentions of Easy Classics to Moderns (Music for Millions, Vol. 17)

I used the Alfred Adult All-in-One books myself, and after getting about halfway through the second I was able to transition to some easier classical music. I recommend going with Alfred as well, and you should also pick up this book as well for scales.

After a year or so of learning, you could get this book that I think has some good pieces that are easier and short. (Any intermediate or advanced people reading this response, this book is excellent for sight-reading).

As an aside, if you are self-taught, I strongly advise that you do not get the book of Hanon exercises that someone might recommend for a question like this. If you do those exercises with improper technique it can really cause bad habits at best and permanent injury at worst.

https://www.amazon.com/Easy-Classics-Moderns-Music-Millions/dp/0825640172

I'm in a similar position as you. I've been playing guitar for about 8 years now, and I'm currently focusing more on piano than anything. I took a few private lessons at my university, and they were a ton of help. I can show you the books my instructor recommended to me.

Frankly, as long as you've got some material and some diligence, you can learn just as much. A background with guitar and music theory will also help you move along quickly! :)

The first consist of these exercises by Czerny. They're a bit redundant, but going through them to a metronome and gradually increasing speed will really help with dexterity and spacial recognition.
http://www.amazon.com/Practical-Method-Beginners-Op-599/dp/0793525675/ref=sr_1_4?s=books&ie=UTF8&qid=1293474093&sr=1-4

The second I began with is Easy Classics to Moderns. Simple to intermediate tunes that will help with sight reading (which I can't stress enough), fingerings, and will give you a general sense of how basic harmony works and has worked for the last few centuries on the piano.
http://www.amazon.com/Easy-Classics-Moderns-Piano-Millions/dp/0825640172/ref=sr_1_1?ie=UTF8&qid=1293474402&sr=8-1

This last one, also by Czerny, is my favorite. It combines the simple exercises of the first book I mentioned, with harmony and melody from the second book. So it will help with coordination and dexterity, as well as sight reading and familiarization with common chord progressions and melody.
http://www.amazon.com/Selected-Studies-Alfred-Masterwork-Editions/dp/0739015974/ref=sr_1_6?s=books&ie=UTF8&qid=1293474093&sr=1-6

Also, it's interesting to convert a few exercises back to guitar, just to break down the barriers between the two instruments. Having a better understanding of both instruments from the other's perspective is pretty enlightening.

Anyway, I'm getting off to a great start with these books. Hope I've helped you out, too! The piano is a kick-ass instrument. I'm hoping to move up the ladder quickly and learn some challenging material soon. But don't slack off with guitar too much!

Cheers, dude. :)

"Easy Classics to Moderns" is a similar range of pieces. (Likely you can find a pdf of it online somewhere if you want to check it out first.)

https://www.amazon.com/Easy-Classics-Moderns-Music-Millions/dp/0825640172

Also good for sight reading at that level would be "The Piano Bench of Easy Classical Music". More of a range here but there's some right from the original sheet music and a lot of more accessible arrangements worth playing.

https://www.amazon.com/Piano-Bench-Easy-Classical-Music/dp/082561824X

There are a lot of resources online - youtube etc, but I prefer books so when I decided to teach myself how to play around 2 and a half years ago I used Alfred's Adult all-in-one, progressive sight reading, and Easy classics to moderns.

Once I felt comfortable enough with sight reading, I just started buying whatever I liked. I also sit down and transcribe the music I like. Just got done learning this track from pride and prejudice, and it barely took a week to learn! It's so wonderful to see my fingers flying across the keys, I can't even describe it.

You might also like flowkey.

Good luck, and I'm sure you'll thank present you for starting - say 5 years from now, when you're sitting at your piano and feeling generally amazing after a particularly good improvisation :)

i was in the same boat as you

havent played since elementary school and just started up again at 21 last November.

i started off pretty slow in the beginning not even being able to play scales or do the most basic music for the first month

but the general plan that I've taken
i've used

http://www.amazon.com/Elementary-Training-Musicians-2nd-Edition/dp/0901938165/ref=sr_1_1?ie=UTF8&qid=1395538406&sr=8-1&keywords=hindemith (this might not be as necessary if you're really good with rhythms?)

http://www.amazon.com/Easy-Classics-Moderns-Music-Millions/dp/0825640172

after doing about 5 of those pieces from that i moved on to beethoven sonata 49, then i moved on to eyes on me (http://ffmusic.ffshrine.org/ff8sheet/ff8-sheet-music.php), suteki da ne (http://ffmusic.ffshrine.org/ff10sheet/ff10-sheet-music.php), and then debussy's arabesque

so if you were looking for a timeline thats how I've been progressing so far with a teacher;

what was kind of helpful for me was just to go in with the mindset that each new piece you're gonna improve on reading and technique so that the next piece will be easier and to pick pieces that helped me; for example, i really wanted to play debussy's arabesque which involves a lot of polyrhythms and arpeggios in the left hand; while i definitely couldn't play it right after playing the sonata, the two songs i played before it was really helpful; eyes on me was great for the arps in the left hand and suteki da ne was great for the polyrhythms