If your target audience includes those who are generationally challenged on the upper end (aka, older), check out this post from David Patt. I'm not quite a geezer (yet), but I can relate to a lot of his suggestions, many of which are good no matter what age your attendees might be. This tip deserves a special callout:
10. Be sure that meeting rooms are well-lit, and that printed and electronic information are displayed in large fonts, so people can easily read copy from close-up and from a distance.
One of my pet peeves is a PowerPoint stuffed with tiny little graphics and squiggles thesays are words, before adding, "don't worry if you can't read it. It'll be in my handout." And then it isn't.
Particularly, though, make sure your directional signage is clear, big, and easy to read. Who wants to walk around squinting at signs to find their session room?