Great posts. Only thing I would add is don't jump right in when you get there. Watch the other guys for about 15 minutes. The beak can give you a good bite and the ink Bloocrab mentioned doesn't just ooze out. They can squirt it. Save yourself some aggrevation and take the time to watch the other people a little first. If you go to the Goat Island Causeway in season there will be about 4 million people there squiding (maybe more!)
so it's no problem to watch and learn. In fact , its elbow to elbow so its not like you'll have to spy on someone.
Get you jigs early on. Most bait+tackle stores run out of the squid jigs early in the season.