...that the seating is first-come, first-served; you can choose any open seat once you walk onto the plane. They allow people to board in order of when they check in (i.e., the first person to check in gets boarding pass A1, the next person gets A2, and so on). There are sixty people who get "A" passes, another sixty with "B" passes, and the remaining passengers get "C" passes.

Southwest allows you to check in precisely 24 hours before your flight, so you want to set a reminder to log on and sign in right at that 24-hour mark.

Southwest does reserve passes A1 - A15 for people who may buy a "business class" ticket that allows them early boarding. Other than that, people can pay an extra fee (~$12 per flight) to get an "early bird boarding" pass that comes right after the A15 pass. Generally speaking, if you check in and print your boarding pass within the first 30-60 minutes of the 24-hour mark, you won't likely fall below the B15 or B20 range.

Families flying with kids who are 4 and under are permitted to board between the A and B groups (i.e., after A60 and before B1), regardless of which boarding pass you're holding. When we traveled with our young kids, we'd try to get an A boarding pass by checking in right away. If we got anything other than an A pass, we'd use family boarding to get on right after the A passes.

Southwest is a great airline with excellent customer service and prices, but they have few frills. They will give you free soda/water and peanuts and pretzels, but there are no movies on the plane. You can generally get free/cheap WiFi on the flight for your own portable devices to watch live TV, which is a nice perq.

Have fun!