Aside from the obvious suggestion of YouTube and Google searches, learning to play piano is best accomplished with a capable piano educator. This will enable you to tailor your personal goals with someone experienced in teaching individualized curriculum, who takes a personal interest in your success and who can readily see your strengths and weaknesses (and adjust curriculum accordingly). This approach will save you time and from creating negative habits in technique due to not having someone see and hear your progress (or lack of). Of course, based on that initial instruction, there is much you can do on your own and with Internet search engines.
Finding a qualified piano educator, however, is challenging. Best resources include word-of-mouth and the local university’s fine arts department list of local piano teachers and piano graduate students. There are good quality music educators found in music stores, but just because they’re located in a music store does not guarantee their capabilities as instructors. Some reputable sources include those involved with piano guilds, Musikgarten, and National Music Educator Association, among others.
One of the best ways to find a qualified piano instructor is through word-of-mouth. Best of all is through hearing and seeing an educator’s efforts with your own eyes and ears! In other words, look for local recitals and attend them. Teachers who are dedicated enough to host frequent recitals are usually quite capable, and care enough about students to enable regular progress in pIano study. Pay attention to each student’s finger dexterity, posture, confidence, reading, memorization, hand position (Watch out for tension!), and especially confidence and poise. The proof is in the pudding!