There are a gazillion parenting advice books out there, and you don't have time to read them all. I read five or six, and this one resonated the best with me, so it's my go-to book for parenting. Every time we come up against a challenge I'm not sure on, I reach for this book and read the calming, gentle, rational, loving solution I need to hear.
Dr. Sear advocates Attachment Parenting, which is certainly controversial but worked well for me. This book extends that approach beyond infanthood and into the helping your child learn to deal with their emotions and resolve conflicts. I relied on it heavily for the first few years of childhood, and checked back on it from time to time for the next few. I wished they put more details specifically on teaching emotion management and less on their approach to caring for infants (which is covered in their other books, and won't help you manage a two-year-old's temper tantrums anyway).
In addition to reminding me of how to be the kind of parent I wanted to be, this book helped me to put typical childhood problems in perspective and keep an even keel. Sometimes new negative behaviours can seem to come out of nowhere and throw your whole rhythm off. This book helped me get it back, and proceed with compassion. It should help you all the way to teenagerhood.