So, How does this whole thing work?

ElKatBee

I've been living in the US with my husband for three years now, and I guess I always figured things were pretty similar to back home in England. We speak the same language, how hard different can it be? I've now learnt not to make such assumptions, and I'm here to ask what I should have done several weeks ago: What on earth is a baby shower all about?

See, a few people, family and friends, asked to throw me a shower, I said sure! Thinking a little party would be nice, but not really being a fan of the center of attention I made a few suggestions... No, things did not go well, I completely put my foot in it and offended everyone involved. Unintentionally, I was incredibly rude and ungrateful seeming just because I really don't know how these things work.

Now, I'm reading through the message boards, and I'm encountering all sorts of hints of rules, etiquette, what's done, what's not, or what isn't any more. Please help me avoid offending anyone any further! How does one be the recipient of a baby shower? How much is too much for a registry? Do I show up first, last, or doesn't matter? Should I know who's going to be there beforehand or will some people be a surprise? What sort of thank you's do I send? Can I open up gifts and play with them when I get them? When do I leave? When does everyone leave? Should I help tidy up? Should I offer to help with expenses? How do I thank the hostesses? Do I need a new dress? (Hope that's a yes) 

Also, I may have mentioned I don't like being the center of attention, I'm not kidding, I start to sweat uncontrollably, can't meet anyone's eyes, say the oddest things imaginable, and then can't remember most of the experience afterwards. I guess I'm asking how much deodorant will I need to put on, and just how much chocolate will I need to recover once home?

 All help gratefully received, it is no condescension to assume my total ignorance.