One of the things that I would like to do in life is to publish a fictional book. I have had a story in my head since I was at primary school and I would like to see if I can have it published as a children's book. The problem is that I have never really been interested in writing long stories. The longest book I've written was my PhD thesis for Chemistry! A children's book would be much different because it is not technical and full of experimental information.
Can anyone write a book if they have the threads of a story already and if so, how does one start? What are the key elements of story writing? Basically, I know there should be a beginning, middle and end but what else? I would welcome any feedback and advice.