NickJr's website has a nice section of free printables for kids ages 2-6.  You can search for activities by age, character, and type of activity.  Characters include Dora, Blue's Clues, Max & Ruby, Wonder Pets, Little Bear, Franklin and more!  Types of activities include Printables, E-Cards, Crafts, Cooking with Kids and more!  Extensive printables fo coloring, cutting and learning - and all free!