I want to learn to play the piano!! :)?

I'm 24 years old and YES I want to learn to play the piano. I would love to learn the notes and all..But I know you have to take lessons and i just don't have that kind of money..But I was wondering , I was talking to a good friend of mine and he said that you could get a good keyboard with light up keys like a yamaha or casio. and he said that there is a way to download the sheet music on your computer or somethign like that and you could , i guess transfer it to your keyboard and the keys will light up and teach you how to play. if so that would be great...I mean I really would love to learn how to read the music , and i actually have an understanding of the notes a little..But just being able to learn my favorite songs woul be so cool..any advice would be great..Thanks :) 10 pts!!!