RE: Hover 3 packs before flying?
if you're talking about radd's, then no it really doesn't =) basically just like aerodave said. If you want to fly more than one pack at a time then you've really got to watch the temps of things because you could over heat something. What I usually do is let it rest for the amount that I flew it for.
good luck with your heli and learning to fly it =) just fly it with whatever you're comfortable with =)