To potty train or not to potty train??

How do i know my youngest is ready to potty train?

1. He fiddles with his nappy when he has been.
2. He stands very still when he has been
3. I ask him if he's done a poo...and he says YES!

Ethey's only 1 and a half and he knows a few words...yes is one of them! I'm thinking it's defnitely time to give it a go...I am however very worried as my house is mostly carpeted :/ 

I think my approach will be to buy a few potty's for the most used rooms and sit him down every 30 mins, and obviously praise him ALOT when he goes!!

I'm excited yet nervous...Wish us luck...Training will commence monday!