Lessons I learned when I wrote my first book

This summer, I have received more requests for advice on how to publish a book than ever, and I am always pleased to respond. Here are excerpts from a letter to an aspiring young author.
My first book was Fun With Jewish Holidays, and the lessons I learned in writing that book have proved invaluable to my future writings.
For young children you need to be literal and specific. It is not enough to say the children played together. Maybe you could describe a few activities on the playground that could be related to the other part of your story such as: “Michael and Lily did everything together. They dug in the sandbox together, they painted at the art easel together and they sat next to each other at snack time. Best of all they liked climbing to the top of the jungle gym where Michael would shout, "Lily, let's fly to the moon." An illustrator needs the author to fill in the blanks with details so they can create corresponding illustrations.
Simply saying Michael didn't like to go to sleep isn't enough? Children want to know why. Expand on why the character likes to do or not do something. You might want to add dialogue here and have Michael express why he doesn't want to go to sleep. It makes the story come alive far more than just a simple narrative. Is he afraid of the dark? Does he miss Lily so much that he can't go to sleep?
Keep names consistent. Michael as Mikey in one part of the story and Mike in another is confusing for young children. When Michael goes to school, you wrote that he puts his school bag in a cupboard. I would change it to cubby which is the term young children are familiar with.
I will let you in on a little secret: my husband takes my completed stories and he sends them to publishers. He does all the secretarial work, and more importantly, he opens the many rejection letters I receive so I never have a reason to be anything but optimistic about by my story finding a “home”.
Finally, let me offer some often repeated suggestions as well as some resources:
1. Manuscripts must be typed and double-spaced.
2. Don’t forget to check spelling, grammar, facts and typos.
3. Art is contracted for separately. It is not necessary or desirable to include art with your text.
4. Enclose a SASE (self addressed stamped envelope) if you wish your manuscript returned.
5. Since the tragedy of “9/11”, almost 1/2 the children’s publishers no longer accept un-agented and unsolicited manuscripts. It changes all the time, so regularly check publisher’s sites.
6. For children's picture book authors, obtaining an agent is very difficult as the royalty has to be shared with the illustrator. Two years ago, I found a list of literary agents and corresponded with the ten that I thought were the best match for me and sadly had "no takers". I still don’t have an agent.
7. THE PURPLE CRAYON is an excellent resource for children's authors, and you may wish to visit the Society of Children's Book Writers and Illustrators , the Association of Jewish Book Publishers and the Children’s Book Council.