I have four pieces of advice for you. The first is to check out SCBWI (the Society of Children's Book Writers and Illustrators) and/or CANSCAIP (the Canadian Society for Children's Authors, Illustrators and Performers) and/or the Canadian Children's Book Centre. These organizations are great for industry-specific information and instruction as well as networking opportunities with other writers and publishing professionals. Oh, and if you're Canadian, The Writers' Union of Canada is a must-join, too.
The second is, don't let anyone tell you there's one way of doing things. In writing and publishing, as in life, the path is often twisty. And that's okay. (During my long break from writing, I constantly heard people talk about writing every single day, which I knew was the wrong advice for me. I knew I had to wait till I felt inspired again! When I was finally ready again, I was fired up with inspiration and exploding with ideas!)
Thirdly, keep in mind that rejection is part of the business. Keep your day job, even once you make a few sales, so you're free to enjoy the process and not stress about outcomes. Remember that even multi-published writers get projects rejected—and often. Which isn't to say you won't be able to sell something that's rejected sometime up the road.
Lastly, feel free to get in touch once you have a rough draft of something! See my Editing Service page for details. (I'm really good, y'all.)