With linking the limbs, it's good to have IK going for the legs and FK for the arms in most uses. Also FK is easier to manage for the spine. I have two books that are helpful for character animation. Digital Character Animation 2 V1 and 2. Also a book I picked up from Hobby Lobby, Animating Cartoons and Animating Cartoons for Film. Both deal with 2-d work but the sections of biped walking and quad have helped with creating walk cycles.