The early training approach, the rapid approach, the readiness approach, the intensive approach. The four most popular training methods that work and at what ages.
This is a good book for potty training it goes over different methods as well as signs to look for to start potty training.
Great read on help with potty training your toddler!
This book was wonderful and was the trick to potty learning for us!
The do's and don't to help you cope with teaching toilet training. Nicely written and easy to follow.