I like to have the kids use graphic organizers for their prewriting, I think it really helps. Several years ago, I used to draw an outline picture of their topic (I drew a house for a paper on household chores) and let them fill it in with their prewriting ideas. I think that makes it more fun. I also use basic ones as well.
You can find loads of graphic organizers for different types of writing here: http://www.eduplace.com/graphicorganizer/
Also if you need writing instruction help/ideas, please stop by TJ’s Writing Area as I’ve got loads of tips and printables there as well.
http://www.talibiddeenjr.com/la_home.htm (scroll down to the writing section)