We have entered the fall candy season. Whether bought or homemade, candied sweets are found in homes from now through the December holidays. It's timely, then, that Anita Chu has just written her "Field Guide to Candy: How to Identify and Make Virtually Every Candy Imaginable" (Quirk, $15.95). In it, you'll find all types of homemade treats, from the simplest candied nuts to the more complicated filled, molded chocolates.