Best website to get a U.S. passport?

[IggyWH]

Couple Q's for a Passport :

1)I see on a Passport website that it says to bring 2 photos. Do you still need to bring photos if they are taken onsite?

2)Everywhere I looked up around me said by appointment only. I can't exactly make an appointment because the hours were all 9-3, when I'm at work. I hope to get to a PO sometime during downtime at work. Will a PO take a walkin?