Potty training usually begins when a child is around 18 months of age. This is because by this time the child has acquired a level of bowel and bladder control that allows it to remain dry for extended periods. Also, it is able to understand verbal and non-verbal communication and make itself understood. If the child is passing more urine at a time, prefers dry diapers, shows discomfort when wet or soiled, and can wake up in the morning without bedwetting then consider these as signals that the time to begin potty training is nigh.
Of course, your child could start showing these signs of readiness before eighteen months of age or maybe later. Both are perfectly normal and common occurrences. No need to worry. It has been noticed that girls invariably show signs of readiness earlier than boys. So if you have a little daughter, you're probably lucky because you'll spend less time potty training her. You will have to be there to help and encourage your child. This means motivating it through words and gestures and very importantly developing an instinct to understand what it is trying to tell you.
A toddler's motor skills are not developed enough to enable him to get out of the pajamas independently or use the potty on his own. So help him. Children learn through imitation so you may want to go through the motions so that the child may observe and pick up the process.
Just as there is no fixed right potty training age, similarly there is no fixed duration for the training process. Be mentally prepared for a six-month routine. If you start late, as it can sometimes happen, then it is possible that the child is mature enough to pick up the procedure faster.
It is a good idea to try and inculcate toilet hygiene in the child through verbal reinforcement of the relationship between potty and bowel cleaning routine. You can begin this from an early age. It will help the child when the time for actual potty training arrives. The objective of potty training is to enable the child to use the potty with almost complete independence and gain freedom from the use of diapers. This is why it is important to begin the process at the right age so that when it's time for the child to step out of the house for pre-schooling, he or she can do with confidence.