Disclaimer: I don't really know what I'm doing, but I'm willing to share what I did. Do what works best for your family and please don't supplant my judgment for yours!
First I'd like to say that I have a child who is eager to please (most of the time) and gets excited about three mini-m&ms. Also Lightening McQueen (aka "Kye") is like Kryptonite for this kid and he will do about anything to get a sticker with Cars on it.
Like I mentioned in an earlier post, potty training occurs at different times in different cultures and this timing is more likely based on the culture and not the child! Ethan and I talked about potty training for two whole months before spending a whole day in underwear. At the very beginning he got three m&ms for just sitting on the potty (clothed or not) and that lasted about a week or so. Then if he sat on the potty that would be good, but he only got m&ms if he peed in the potty. A couple of times a week I would put him underwear for an afternoon so that he could feel what it was to be wet. When he went I would not fuss at him or make a big deal we would just talk about the wetness and that our goal was to keep Wall-e, "Kye", or Elmo dry!
Finally when the big day came to start training I put him in underwear and made him sit on the potty every 40 minutes. The key to this plan is to always have liquids available. I didn't really force him to drink, but I did offer plenty of salty foods. I also added a sticker chart in the bathroom and he got a sticker every 40 minutes when his underwear were dry and another one if he could "go" on the potty. Of course m&ms were still part of the system and I would be sure to bring a canister of them wherever we went. Rewarding for dry underwear was my friend Betsy's idea and I really think it has contributed to our success. Ethan even says now when he is in the bathroom, "Kye dry!"
If you read past posts you'll also see that we did use diapers at night and pull-ups only for nursery and VBS. These are only used when an accident would require major clean up (sheets, pillows, stuffed animals, softees, etc.) or would uneedly inconvience someone else. They do have little pictures on the front so I can tell if he stays dry and reward him as such.
To all you moms out there who are considering potty training, go for it! What's the worst that could happen? If you have any questions please feel free to post them. Betsy did post descriptions of the "phases" of potty training over on Tarnished Teapots and it is great!