Finally, keep in mind that the format of the poster is completely free, so you can do with it what you want. Update: Last year I saw some people hanging iPads on their posters, thereby making them dynamic! I thought this was a really good idea. Keep in mind that you can attach whatever you want to it, and be creative! If you have some interesting samples you want to show, that is fine too. Take advantage of the third dimension :) Also, people attach their papers and resumes just in case someone is super-interested in their work. Finally, don't forget your business cards (clever idea: put your talks time & location on the back)! I've had situations where I wanted to talk to a candidate, but they were not by their poster. The time is short, and employers will not stay around waiting for you... sometimes grabbing a biz card and moving on is the best you can do...
SOME LOGISTICS: "Last year the size of the poster boards was 4 feet high by 6 feet wide. Unless you receive an update from AIChE or from us that states differently, you can assume the same size this year. Please limit the size of your poster to 3ft tall by 4ft wide. There are usually pushpins available, but I recommend bringing your own, especially if you are posting individual sheets of paper. Please plan on arriving at least 15-20 minutes before the start time of the session to put up your poster."
Official guidelines are here: http://www.aiche.org/resources/conferences/programming-resources/poster-session-faqs
TIME MANAGEMENT: some times people come up to you and start asking questions about your work... however, they may not be people that can give you jobs (i.e., some random student or postdoc who just wants to learn about your research). Given that an employer may see that you are busy, and as a result skip your poster, I highly suggest that you understand who you are talking to before you invest the time.
ps: I remember my first experiences were that no-one comes up (I started as a grad student, but you really need a postdoc to be taken seriously). Do not get discouraged! There are a lot of you, and you are all at the top of your game. Also, I think landing a job in academia is harder than industry. So, try to learn from your experience and make your package more attractive for the next year. You will get some interest eventually, I promise.