Reddit mentions of A Dozen a Day Book 1 (A Dozen a Day Series)

John Thompson's Easiest Piano Course is as good a place as any. Edna Mae Burnam's A Dozen A Day books are also worth using.

Lots of practice! I have tiny little hands so I have a hard time playing some of the stuff I wanted. My teacher just had me practice the tricky parts over and over and eventually I learned to stretch my fingers a bit. I think honestly the biggest part of being able to play is practice- I'd get one of those warm-up books (or make your own!) because they really help you learn to move your fingers the right way and play more smoothly and such. Even in college my teacher had me warm-up with scales and different little ditties. It helps build up strength too, for sure! :) I used (and still do use them because they're kind of fun) the Dozen a Day books. They have all these little drills to do that really help you get comfortable moving your fingers certain ways and building strength :)