Try "Once Upon A Potty for Him" on DVD or VHS. There are also several books about it too. The dvd is for your son and the Dr.'s excerpt at the end of the show is for the parent's information. It will give him kid-friendly instruction about using the potty and it tells you about the "readiness" signS.
I have 4 children and my littlest is 1 year old so I'm a mommy who has recently gone through this because my children are still little. I would definately wait if I were you! I read where several moms said "go ahead" but I would disagree. One mom said she started early and had the child potty trained by 1-1/2, I think. That's a LONG time to be fiddling with it. If you wait until your child is ready then you'll actually be able to get him potty trained faster and not have to drag it out over several months. It's equally as frustrating to clean up an accident while potty training because it gets all over and it's no fun especially when you're out shopping. While he's still this little it's usually still contained in the diaper 9x out of 10.
My friendly advice is to not make it such a big deal. Just pulling the diaper off is not the only sign of readiness and you want potty training to be a successful, positive experience instead of a constant struggle with your child. Bottom line...do what works best for you and your son and after kindly listening to all the advice from friends and family...don't allow others to influence your decision:)
It'll happen soon enough! Some kids do it sooner and some later. It happened sooner for my girls than it did for my son actually. Also, it's not like he'll still be in diapers by the time he's off to preschool/kindergarten. Right now he is still a baby. Try to enjoy this time cause they grow up too fast.
And, as for the walking in to a poopy or pee-pee mess after naptime...well, it happens and you just have to keep your cool and clean it up. What can I say...Life is Messy:) and this too shall pass and you'll be onto the next stage. Best wishes!