Potty Training advice

So I guess we're at the beginning of the process with the potty around here. I realize Karis is barely 18 months and I am not in a rush. However, she is showing some signs of readiness. She's talking about the potty a lot, tells us about pee-pee and poo-poo, though I don't think it always coincides with the act of doing it. We borrowed my mom's little potty and Karis asks to sit on it a lot - a few times every day. Last week she pooped on the potty twice and today jumped up from the potty and peed on the floor. So, with the list of her symptoms :), what would any of you suggest? books, materials, when to start training panties (she has been doing pull-ups during the day), should I just let her go gradually b/c she's young or be more intentional now that she's showing signs? I don't want to start too early when she's not really ready, just to go backwards. I would love to hear some tips and stories from my experienced mom friends!