So far I have been able to assist my 1.5 year old to the potty about 3 times a day. I try to bring him to the toilet every 2 hours on the hour (10-12-2-4-6-8 etc) He has been dry on several nights that he sleeps through the night. He has actually been going to the toilet since he was about 4 months! However, he does have occasional leaks and misses that we have to clean up. When he was capable of sitting on the toilet we took him every 20 minutes. Before he was over 20 lbs we were able to hold him over a public restroom toilet and he would actually go! Now he is too heavy for us to lift over a toilet so we can only set him on the little potty at home and regretibly we have to let him go in his diaper until we return home or have a little potty available. That is one of the inconveniences of modern society.
You too can start potty training a youngster before the age of 1 and hopefully be done with leaks by the age of two! Check out this link for further information. Keep in mind it is a "green" website so it may seem kind of different to mainstream thinkers.