i. If a conference website says proudly, "We have 1800 delegates coming", I presume that means that there will be a lot of people there. However, do many people actually turn up to poster sessions?
Generally people wander around poster sessions. Most poster sessions are set up in a large room and you need to be there for the entire time of the poster session. For example... a paper session will probably be 1.5 hours... but a poster session can be 6 hours. You just need to be there by your poster to chat with people who come by.
Additionally... don't sit around looking bored... you can certainly (and should) start to chat with people as they walk by and 'pull' them into looking at your poster.
Make sure your poster is big enough to see.
If you have a laptop set up a powerpoint slide show (on automatic) that runs to show further information. erm... point this to the audience!
ii. When they say that you should bring plenty of velcro to attach your poster to the boards, do they mean the self-adhesive type that one can buy from stationery shops?
Yes
iii. How do you carry such a big poster safely on the train? I'm trying to decide whether to do that, or accede to a relative's offer to drive for 10 hours.
Go to Staples and get a poster mailing tube. Roll your poster up and insert it in the tube. You can even go 'whole hog' and get a reusable fancy carrying tube with a shoulder strap. Additionally, you might approach your university's marketing department and see if they have one you can borrow. They have a lot of experience in traveling with 'posters' to promote your institution.
iv. Any suggestions for conference behaviour generally? If this was my (small) discipline, I'd know how to behave.
I find that the best conference behavior is to be friendly and to chat with people. Don't sit and wait for someone to approach you... but be outgoing and friendly.
I was just at a conference in Valencia and I have to say that the huge number of doctoral students from Nottingham really impressed me with their demeanor. Several of them introduced themselves to me and asked me when my paper was being delivered. They then wrote down in a notebook the time/day/room.
I'm not saying that they were all there... *laugh*... but their behavior was respectful, engaging, and showed an interested in their surroundings.
Things NOT to do...
1. Get drunk
2. Argue with a panelist (even if you think the panelist is wrong)
3. Wear innapropriate clothing to any session