This all sounds like a great plan - you're ready!
Yes, yes, yes! Do print out a label for the back of your cards...that's just what I was thinking as I was reading your most recent post...go for it! Get people on your site.
You should take a traffic reading before the show so you can really watch what's going on - have you installed
Google Analytics yet on your site? If not, do it now - it'll be fun for you to be able to see the patterns and the detailed info is amazing.