Writing is a difficult subject for me. I am going to try a daily writing curriculum that teaches slowly and see how that goes for a month or two. I don't have the book on hand that I am going to use, but when I pull it out I will post it. However, if you are looking at some different books, I would look for something along those lines.
I have an 11 yr old, 8 yr old and 6 yr old. Explaining writing a little at a time seems like a good fit for my kids and for me.