Because they mostly contain simple plots, fairy tales work very well for introducing second graders to basics of story structure: rising action, climax, and falling action, for instance. You don't need to use these terms. Instead, ask students to help you draw a plot line on the board after you've read a fairy tale together. Mark where important events occur on the line, and get them to determine where the most important point lies. Ask students if they can think of other stories with a similar structure.
Famously, fairy tales contain morals. Little Red Riding Hood, for instance, teaches children not to trust strangers. For second graders, trying to determine the moral of a specific fairy tale can be fun and an important learning experience. Read a fairy tale aloud, and ask students what they think the moral of the story is. Lead a conversation on why that moral is important in their lives. If, for example, the class decides that the moral is, "Sharing is good," ask them to identify other situations in which the same moral applies.
You can use fairy tales to get your second graders to respond creatively. Have students draw a picture of their favorite scene from a fairy tale you've read in class. Ask them to give the picture a title, or to write a caption under it. Post the pictures around the room. Alternatively, break your students into small groups and have them act out a favorite scene from the fairy tale they've read. Allow them to present their scenes in front of the class.
Reading fairy tales is fun, but writing them is even more exciting for second-grade students. After you've read a few fairy tales in class, have students write their own fairy tale. Emphasize that it should have a clear moral, that it can contain magical elements and can be scary or exciting. Have students brainstorm ideas for their fairy tales before they begin writing. Help them come up with valuable lessons that should be learned.