I went in to get a passport this week and thought I'd be late but as long as you sign in before a certain time they will take you. Just make sure you get there before 2:50ish (if you have all your documentation).
The guy that was helping me was so kind and efficient and not just to me, but to everyone he helped. He was calm and patient with anyone's questions
What helped me, was knowing I could write personal checks rather than bringing in money orders. You need one check/money order for the federal fee and a separate check to pay to the city of Chandler - so bring your check book, driver's license, birth certificate and forms completed online (although they have forms there). Their signage walking you through steps is kinda small but helpful. Made this process so much easier than I thought!!