Question: I’m a guest at a science fiction convention this weekend, and I’ve never been to one. I’m on some panels. I write paranormal romance, not science fiction. What can I expect, and will the natives be friendly?
I've done cons for years.
There's no great trick to it. Show up on time to your panels and have a copy of your book so you can display it in front of you. If it’s an ebook, have a nice graphic of your cover printed and pasted on heavy cardboard with a means to set it upright.
Have some water or a bottled soda on hand. Be natural and funny if you are able.
Have something intelligent to say about the panel topic and don't just talk about YOUR book because sf fans have an aversion to blatant PR. If you know nothing about the topic, admit it if anyone asks you a question and ask a question or two to the panelists who do know something.
It's also a good idea to read the bios of your fellow panel members so you get some sense of who they are and what they write. Most con programs or websites provide a bio of each guest.
Having bookmarks or some other freebie for the con’s freebie table rarely is worth the money, most end up in the garbage at the end of the con, but do have a business card or postcard which is printed with your book information, your name, and website to hand to people who express interest in your book.
An alternate business card with your complete contact information is good to have to pass along to other pros or someone you want to keep in touch with.
If you do a reading, pick something short and understandable and practice beforehand. If you have time left over, ask for questions or just chat with your audience.
As far as dress, casual business will do. A nice pair of pants and a blouse. Maybe a dressy jacket if the hotel is cool and most are.
SF fans are much more open to paranormal romance and woman writers than they once were. The memberships tend to be dominated by women who usually read paranormal romance as well as urban fantasy, etc. Those who don’t will be doing something else when you do panels so don't worry about them.
In your free time, network like crazy with fans and other writers and attend some panels you aren't on.
Many of the fans will be wearing neat or silly costumes but don’t be deceived. Most are highly intelligent, educated, and have jobs that pay more than yours does. To start up a conversation, ask them about their costume. Remember that you are the alien (mundane) here, not them.
If the con has some professional publishing guests like agents or editors, you can usually find them in the bar or their private con party suite.
If you don't read sf, fantasy, or urban fantasy, a good topic of conversation is sf/f media if you are a genuine fan. You can also ask for reading recommendations, and the dealer's room is usually full of books as well as other neat things.
Mainly, enjoy yourself. Cons are a lot of fun.