Potty training- how to start?

[Newfamily2014]

Hello, my dd is 19months old and tells me that she is doing a poo and needs a nappy change so I thought I would have a go at potty training.

I have bought her a potty and she enjoys sitting on it (not yet without a nappy). She sees me going to the toilet and understands the toilet, I think!

But I'm not sure how to start potty training..
Where do I start? what do I do?

advice welcome please!

Dd is same age and not always aware she's pooed, or not willing to tell but still interested. We've bought a toilet insert and every evening before bed we pop her on the loo. She's straining and keen to do something, positive and hand washing etc after even if didn't manage anything. She managed a pee today.

Thinking well just do this for a while until she can tell us she needs it before she actually goes.