You've been given a lot of great advice! Might I also add in a recommendation? See if your local library has
"House Training for Dummies." That book alone really broke it down for me and helped me to see the whole potty training process through Amelia's eyes. I have not had any problems whatsoever since I finished reading that book and applied several of it's philosophies to our daily regimen.
HTH & Best of luck!
Katy