Everyone Poops by Tari Gomi. You don't need to read it in advance. You read it with your daughter while she sits on the potty. Actual training - we just put DS in big boy underwear and took him to the bathroom often. (Where we read 'Everyone Poops'). I do recommend NOT starting any longer books in the bathroom. DS wanted to sit on the toilet long enough to read the whole book whether or not he had already pooped.
ETA - My son potty trained at 25 months. He did not initiate the process. He had frequent accidents for 4 days, a few more over the next 3 days and two more accidents over the next 4 months. He was in underwear the first day we started training. He never regressed, we never had to try again. He could climb onto the toilet (with seat cover - never used a potty - ick) with the help of his step stool. We did not night train for several months because we (not DS) were concerned we would have to get up in the middle of the night to get him out of the crib. Once we did night train (~27 months), he had night time accidents maybe once a week for a month (4 accidents or so).
I so don't get the objections that kids who train early have their parents trained. Um, parents with children in diapers are 'trained'. We are trained to notice when the need to be changed, rush immediately to change them (we don't worry that they can't help with this by undressing or re-dressing) and disposing of the dirty diapers. I would rather remind my child to go to the bathroom every 2 hours (we never took him every 20-30 minutes) and know he is clean and dry the rest of the time then constantly be watching to see if he is dirty.
It was also VERY helpful that daycare took the kids to the bathroom after meals, nap and at 'potty time'. It just made it an expected part of the routine. I see no problem in enlisting the help of your care provider in training.