Yodel, They will post a ring time and ring number for all working dogs. (i.e. boxers 8:30 ring 2, rottweilers 8:30 ring 2, dobermans 8:30 ring 2, etc.) They will have two shows per day (am & pm). You have to check in before your ring time to pick up your folder and then you wait for your breed. On Saturday we had an 8:30 ring time but rottweilers didn't go in until after 11:00 and then we had a 1:15 ring time and didn't go in until almost 4:30. I didn't get out of group until 6:15. I didn't stay for BIS that day. They tend to not be as organized.
You show your dog similar to an AKC show. The steward will call your class and ask for folders (the folder is where they put your certificates and critiques). The judge will bring all dogs in that class in at once, go over each dog, down and back and around, just like AKC, and then will place the dogs 1st, 2nd, 3rd etc. Then the dogs are pulled individually and critiques against the breed standard. You have a one on one with the judge and he/she will go head to tail telling you the good, the bad and the other and you are given a written critique and rating in the same manner in which dogs are rated in European Sieger show (V1, V2, SG, S etc.).
I've been to IABCA shows that were well run and moved along quickly and I've been to some that aren't and drag on late into the evening. Yodel, I hope this helps.