I trained my son in a day using Toilet Training in Less Than a Day, by Nathan Azrin.
The book dates back to the 70's, and is written in English English, which makes for some weird/interesting bouts of reading, but the method is extremely effective. My boy was trained in a day, going to the potty for pee every time, asking for a diaper for poo every time (he was a little afraid of going potty, it took him 1-2 weeks to also do it in the potty), and needing a diaper for the night for only 2 more months. All this with just one day of effort on my part, fun on his.
Other friends of mine have used it too and had the very same results. Don't understand why it's not in all pediatricians offices, it would save so much angst to so many parents.
Have fun with it!