We are using the “Piano Adventures” series. My DD9 and DS7 are using it almost completely independently. I just sit in a few minutes every once in a while and make sure they have read all the instructions, ask them questions to make sure they know what they are supposed to be doing, and then let them go. I do have music background, which helps because there are ‘Teacher plays this: ” sections, but mostly of the time they just ignore those anyway. My DS7 in particular is really moving through the books, all on his own. They are only on level 1, so I don’t know how far they will get before I have to get more involved, but so far it’s working.
http://pianoadventures.com/
They also have a series targeted at adults. Here is a quote from the website:
“This series includes lessons, technique, and theory together in each volume for ease of use. Each unit includes a “3-Minute Technique” page to develop finger dexterity and a “Music Theory” page to develop understanding of rhythm and harmony. Though study with an experienced piano teacher is recommended, adults interested in beginning on their own will also find these books invaluable. “