What is some general advice for demoing wireframes to clients? [on hold]

I've been working on a web app, and have gotten the wireframes pretty far along, based on initial in-house research & discussion. The biz guys are eager to set up some demos of the wireframes to potential clients, and I'm eager to use those as an opportunity for more research. Any general advice about what questions to ask, things to avoid, approach, etc.?

TIA