Worldcon is coming up, and a lot of new writers, or writers who've been around a while and who've found times bumpy due to the economy, are going to be anxious about using this opportunity because received wisdom says that cons are for:
making deals
meeting editors and agents
and most of all
selling your work.
Steve Miller
passed along this link that may be of help.
Scalzi's thing about behavior on panels is spot on--I don't know of any fan who has been impressed by the Tower of Books in front of the writer on a panel, or the writer who doesn't discuss so much as wait for their chance to grab the mic and say "In MY books . . ." and speechify for as long as they can get away with.
The short version can probably be summed up as: nobody likes a hard sell, whether it's cars, or insurance, or books.