There are many books published which set out a series of lessons in a 'one step at a time' fashion.
I have found the Alfred's Basic Piano Library very useful as a starting point and so many of my students start their journey with an Alfred's Book. One of the reasons I have kept coming back to this series is that there is a very large number of books that a student can access along the way from classical to modern, TV and movie theme songs, broadway to hymns that fit with the levels within the course. Most students find plenty to study at their own level that is engaging and rewarding.
Many similarities exist between the various publications. The differences seem to be mostly in the order in which the concepts are introduced, the amount of repetition offered for the concept and the depth of the concept covered at the level in which it is introduced. As students differ widely in their ability to grasp a concept and speed of assimilating the information, different courses seem to work better for some students.
Method books are great for offering a little of many styles to help discover what particular style the student wishes to learn more pieces from.