The character list is available by phone each morning as well as at the towel stations. We took a photo of it at the towel station by the infinity pool every day. (The other towel station wasn't so liberal with the times guide for some reason.) The characters on the list as of October 2017 were: Mickey, Minnie, Pluto, Goofy, Donald, Chip and Dale, Daisy, Stitch, Moana, Duffy, and ShellieMay. All but Daisy were out and doing photos during our visit. We were able to meet each of the characters multiple times over the course of a week, but ShellieMay only came out once (and I was so happy she did!). We met Goofy, Duffy, and Chip and Dale the most - even just hanging out and bumping into them at the pool or on the walkways, or wherever. The PhotoPass photographers were at most character photo opportunities, but not all, so be sure to bring your own camera just in case.
We found the character interaction at the meals less entertaining than at the character meet locations. We never waited more than 15 minutes for a character, mostly because they switched characters every 15 minutes... so don't line up too early. The CMs are great at identifying who the line is for, and breaking up the line between characters, so you don't accidentally line up for the wrong one.
Also, Moana often shows up at the fire pit story telling sessions, though she won't meet and take photos there.