I started the piano as an adult and I already played the flute, so my first book wasn't really a complete beginner's book.
I used Bela Bartok's Microcosmos book 1 as my first book. Then I had "CLassics to Modern" book 1 and moved to Fanny Waterman's "Young Pianist Repertoire"Book 2. After that I passed grade 5. All of this happened within 2 years.
Then I had a few years break from lessons due to my job as I had to move all over the country, but I managed to played various "random" pieces at times. I usually hear a piece from somewhere such as friend's place, the radio. If I decided that I like it I will have a go! I try to get the "Urtex" Editions of the piece if possible. Examples include Chopin's Waltzs, A few Mozart's sonatas, Bach's French Suite, Debussy's arabesque etc....and lots of church music as I played the piano for my church for a while. Occationally I "get stuck" as I didn't have a teacher to help me and had to give up a piece.
Recently, I got a "more settled" job and "re-started" having lessons. My teacher suggested I do grade 7 and so I am playing the abrsm grade 7 exam pieces at the moment. I am quite pleased that I did managed to make a little progress the years even when I was "on my own", but have unfortunately accumulated a good number of bad habits!
What about you??