2. Click through to see who the organizer is - makes it easier to spot who the group is
3. Click through past meetup events to see who has attended before. This is helpful in that you can seek out the regulars as know the ropes.
4. Ask the organizer is they need any help ahead of time. This is always (always!) very appreciated from the organizer as there are always tons of things that need to happen for the event to go well.
5. If you have time, msg one of the people going (or even better one of the regulars) to see if they are open to grabbing a coffee to chat about Ruby (or the meetup event topic). This is a big win for you because when you go to the meetup, you'll already know someone there. Plus you can ask any type of question (even if you think it's not a good one) to someone in a relatively private 1-on-1 setting instead of a group setting where psychological dynamics really kick in.
6. Once you are there, show up extra early (~around 15 minutes). Usually the organizer will try to get there extra early so if you are there right as they get there. It's much more friendly and casual to meet the organizer.
7. If you do #6, then as people arrive, the psychology is different because it's new people arriving, instead of you arriving later.
8. If the meetup event is not to your liking. Figure out why you don't like it and leave. No point in wasting time.
9. Write a very small and brief thank you note to the organizer afterwards. This rarely if ever happens, is very much appreciated and the organizer will definitely look out for you next time. Which, if you go to the event again, makes you a regular!
10. Have fun! =)