Here is how I usually start:
The night before you start put away ALL diapers.
Have all of your supplies ready.
Wake up and take off diaper. Starting with a fresh bath is good too! Explain that they are big now and all the diapers are gone. Now when they need to go potty or poop they need to tell mommy or daddy and run to the potty. Show them where all the pottys are.
I usually start by showing them our routine for going potty.
Run/walk to potty
pull down pants and underwear
show them how to wipe properly
pull up underwear and pants
Be prepared for the first few times to be accidents. I usually ask them every hour or so to try and go potty. I try to stay away from asking them if they NEED to go potty instead I say something like, "Okay lets TRY and go potty." This usually avoids the fight because usually if you ask them if they need to go they will always say no and then two seconds later you are cleaning it off the floor. Go figure! So about once and hour we go the the potty and go through the routine. Even if they don't go. It is great practice. Try not to get upset when they sit on the potty for 20 minutes and don't go and then they stand up and have an accident. Just reinforce that accidents happen and to try to make it to the potty next time. Anytime they have an accident take them to the potty anyway and go through the routine. Whenever they go potty in the toilet we do a potty dance. Some people give treats, but I didn't want my kids expecting treats just for doing something that big kids are supposed to do. So we do a potty dance and have even called grandma to share the news.
The first few days can be pretty discouraging but stay with it. Some learn faster than others. Also make sure than your husband knows the routine too. Consistency is the key, at least in my experience.
As for nap time and bed time. I usually start off with pull ups. I have found that my kids have really not needed them. They would go potty in them if they had them on, but when I didn't put them on they stayed dry. Give it a try. If they are consistently wetting the bed I would use them. If you want to potty train pull up free my sister will wake her kids up in the middle of the night a few times to "try" and go too.
Each kid is different and learns differently, but in my experience they catch on pretty quickly as long as they know exactly what to do and how Mommy is going to react!