Hey-I can't go this year (on night float 🙁 ), but it's really fun! The resident section is big, and everyone is very friendly. Dive right in and go to some of the other presentations as well-there are lots of clinically oriented ones (on the website or in the guide). Bring comfortable shoes and an umbrella.
And definately visit the exhibitions, as OBP mentioned. Lots of freebies-more pens than you could ever use in your lifetime.