There's many great sites out there to help you make a good poster(1) and teach you how to present it. I haven't seen a lot of practical tips on actually bringing the poster to the venue.
1) Use a real poster carrier. Preferably buy your own. Really, they're lighter and thinner than a cardboard tube, there's no end caps to lose, and the strap makes them much easier to carry. And with your own tube you can mark it so it's easy to find in a sea of similar ones. To my surprise, they're also really cheap. I got a new one for this trip at Daiso for just 200 yen. I don't think a cardboard tube that size is any cheaper.
2) Don't just shove the poster into the carrier. It can scuff the edges and it makes the poster hard to get out again. Roll it up, wrap a sheet of copy paper around the middle and secure it with tape. It'll lie loose in the carrier and drop right out into your hand when you open the tube.
3) Make a backup. Always. You don't want to be the poor sod that's rushing about in a panic trying to find a place to print out an A0 poster the morning of the conference. The world is a big, scary place for a poor, helpless poster, and anything can happen on the way. You may lose your luggage (not all airlines allow you to bring it into the cabin), and you can so easily forget the poster in the airplane, in a cab, or in a bathroom. Never mind that it can get stolen, run over or destroyed in any number of ways.
The best way I know to backup is to print a second copy. Design your poster so you can cut it either lengthwise down the middle or sidewise into three pieces. Roll these pieces together into a short tube that will fit into your carry-on. Sure, a visible seam is a little annoying, but it's much, much better than having no poster if something bad happens to your uncut copy.
Here's the poster I'm presenting. Notice how I can easily cut it down the middle without
destroying anything. With a bit of tweaking I could have cut it lengthwise instead.
4) Don't bother bringing tacks, tape or anything like that. I've never been to a conference where such things weren't abundant. A couple of thin ink pens in different colors is a good idea, though; you may find a mistake or something on your poster and they'll let you do last-minute corrections or clarifications.
All done, ready to go. See you in a week!
#1 I actually favour dense posters with plenty of information. I want to be able to read and understand the work without having to ask the presenter anything. They may be absent of busy talking to somebody else, after all.