If you want to write a story, but don't know where to start, you'll find a great list of writing prompts suitable for children and young adults over on my Brain Bunny Blog. You'll also find a list of competitions and journals which accept writing from young people on the Brain Bunny Links page.
Would you like these colouring in pages from my picture book Aunt Kelly's Dog? The illustrator, Ian Garmonsway, has kindly allowed me to use these, and offer them to you for free. To get your downloadable copy, simply join my mailing list (this is the simplest way to deliver them to you.) I know it says "for kids" but there's no age limit. I'm a pretty big fan of colouring in myself too.