Flexible shifts hiring in St. Louis - what worked for you?

A grocery chain and a hotel near St. Louis are hiring part-time staff. I have read a lot of threads here and could not find my exact situation. They can give a schedule two weeks ahead. How many hours do they guarantee?

Ask whether the schedule is posted in advance and how they handle swaps. It matters a lot with kids.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.