Time to Potty Train?

I decided to put our potty seat out just to start talking to Rylan about potty training and see if he was interested.  When Carter needs to use the downstairs bathroom, he'll often ask Rylan if he needs to go too now.  Carter will try to help Rylan pull down his pants but is never able to and I have to step in.

Yesterday Rylan wanted to sit on the potty seat (and Carter had to sit next to him on the stool).  Rylan would sit for a couple of seconds and then stand up and look in the potty and give me a "where's the pee and poop?" look.  It was really funny.  I kept asking Carter to tell him what to do in hopes he would have a child's perspective/explanation that Rylan would understand.  After several "attempts" nothing had happened and Rylan was over it.

My plan is to potty train Rylan this summer when we have a week at home.  Since Rylan is only going to school 2 days a week next year, he doesn't have to be potty trained.  Though I'd like to try to have him potty trained but have his teachers put a diaper on him for nap.  We'll see if he's ready though.  Carter was 3 1/2 when he was finally potty trained and he was ready then and it was easy.