American Veterinary Society of Animal Behavior
Common behavior questions and scenarios
Animal Behavior Research Institute
Videos and podcasts on the more common behavior problems in dogs and how to modify them
Indoor Pet Initiative
Basic pet care tips and tricks to prevent and deal with behavior issues and to generally keep pets happy
Association of Pet Dog Trainers
Dog trainers do not have to be certified by any organization to be excellent trainers and there are poor trainers that are certified by every organization. The APDT trainers use only positive methods of training and you can find trainers using their search feature.
Activity Food Toys (aka, Kongs and the like)
These are good to try with the dogs that have too much time on their hands, eat too quickly or need some sort of other distraction for 5-30 minutes.