The world of teenager Jessica Darling is circumscribed by parents who are utterly clueless, an older sister who marries and becomes pregnant--much to Jessica's dismay and wonder, the loss of a best friend, a churning attraction to mysterious Marcus Flutie, and the dangerous and sometimes hilarious society of the girls at her Pineville, New Jersey, high school. Jessica is an insightful and sometimes obsessively observant narrator of all of these situations in two novels by Megan McCafferty, a former magazine editor turned author. McCafferty introduces Jessica in the debut novel, Sloppy Friends, extends the fun in the 2003 sequel, Second Helpings, and continues to work on the angst-ridden teen in a planned third volume. McCafferty has also written a prequel short story about Jessica, "Fifteen Going On. . . ," included in a collection of stories she edited, Sixteen: Stories about That Sweet and Bitter Birthday. On her Web site, McCafferty deals...