The unit of study that many third graders will be working on this month is narrative, but raising the quality of those narratives. It is important for students to be able to develop stories the best that they can since narratives are included in other genres--nonfiction, argument and informative. Stories will be part of most essays as they are used as evidence in those genres.
A way to start this unit is to make lists of possible stories from their lives in the writer's notebook. The lists should be of significant events in the lives of the students. They might list the first or last times they did something. These type of stories will be emotional happenings and therefore meaningful entries. They could make a list of a time they learned something---maybe a time an important person taught them. That also could evoke a strong emotion. They might generate a list of major issues---bullying, family issues, being a new student.
After a day of creating this list, students can then begin doing quick writes in their notebooks on various topics from the list. These small entries will take one to two days. When a student has a story that they feel could be developed into something that could be a meaningful piece, they will want to begin drafting outside the notebook. It is time to put their "blood, sweat, and tears" into the piece.
It will be at this time that you will want to have mentor texts for the children to model. It will help to have these texts be new, not something they used the past years. A few suggestions that I have used are: Let's Get a Pup by Bob Graham, Owl Moon by Jane Yolen and Hesse's Come On, Rain! Having on hand books that have various beginnings or endings help students learn how to craft those things.
Once students are started with this unit you will be able to see what areas need to be revisited to raise the quality of their narratives. Let the students' work drive your instruction!