If I am a US citizen and I have never had a passport before, how long will it take for me to get one? How early do I need to apply before I plan on going abroad?
I was in the same situation a year ago. It took me about 4 weeks to receive my Passport in the mail. Keep in mind, that you will need to send your original birth certificate with your passport application so you will be without that while you wait. According to Consular Affairs, it takes 4-6 weeks for routine service but you can opt for expedited service.
All things considered, I would say begin applying for your passport at least 2 months in advance of your travel date. Any later, and you may be cutting it close.
tl;dr: Official wait time is 4-6 weeks, but it's about 2 weeks during the off-season. No official statistics exist, but you could call or email them to ask, or just ask at your post office.
According to The Bureau of Consular Affairs, 4-6 weeks or 2-3 weeks if expedited.
However, these time frames are not at all accurate, at least for off-peak months (roughly around Sep-Mar ?).
Fri, Feb 1, 3pm: I applied at a post office, was told that expediting is not really going to get me my passport any faster and to call if I hadn't got it within 2 weeks.
Wed, Feb 13, 5pm: Notified that my passport was printed and should arrive by Tue, Feb 19.
Wed, Feb 13, 8pm: Received tracking number indicating arrival by Sat, Feb 16, 8pm.
Sat, Feb 16: Arrived.