R.B.
Thanks for asking this question. I am working on potty training my 31 month old son and my 18 month old daughter. The 3 month old isn't ready yeat haha. We have 1 potty and it isn't working out the greatest, so I would recomend 2 if you can swing it.
We have big boy/girl underwear and they get to put them on when they get up in the morning. Then they can keep them on as long as they keep them dry, after that they have to wear diapers for the rest of the day. They usually make it to lunch. And I usually end up cleaning up a puddle. If you have couches that they sit on, I would recomend getting some absorbent padding for the cushions if you are gonna try this method, my daughter peed on one of her pillows and I am trying to get the smell out.
I wish you much luck with training. And I love reading the suggestions from the other mom's and hope to impliment some of those here.