Southwest boarding is truly ridiculous, but it's not as bad as the rumors. Here's how it works:
1. Southwest boards its planes in three and a half groups. First are the people with "A" boarding passes (more on those in a second), then families with children under four (?), then "B" boarding passes, then "C" boarding passes There are a total of 60 passes in each group). There are no specific assigned seats - you can sit in any available seat once you're on the plane.
2. You are assigned a boarding pass group and number when you check in online. This is the tricky part, because people who REALLY want to board forst will be at their computers at exactly 24 hours before the flight, to make sure they get "A" passes. SW no offers Early Bird Checkin, where for $10 per ticket per flight, they'll automatically check you in 10 hours early (which they say does not guarantee an "A" pass.
3. At the gate, there are posts with numbers on them. When the flight is ready to board, those with A passes line up by number near the posts that include their number (so pass #34 lines up near the post that says #30-35.) Then they board. Then the families, then the B passes, then the C passes. If you have C passes, you may not be able to sit together. With A passes you will, and with B passes you might.
This all sounds a lot more complicated than it really is, but it's still a huge PITA. HTH