The questions that arrive after the box does.
Buying helium
Find a welding-gas or industrial-gas supplier locally. Do not order helium online. Suppliers sell by the tank and handle repeat accounts routinely.
A 200 cubic foot tank runs about $300. For a blimp, the first fill uses most of a tank on its own, so plan the first order accordingly. Ask about cylinder rental terms while you are there, because that is the cost people forget.
Topping off
At roughly one percent loss per day, nothing fails suddenly. The envelope softens and the blimp starts riding lower on its tether.
Use that as the gauge rather than a calendar. When it stops looking taut from the road it has stopped doing its job. In practice that means adding gas every three to seven days.
Flight height and the FAA
Below 150 feet above ground level the FAA is not part of the conversation. We fly at 120 feet, deliberately under that line.
The one exception is controlled airspace. Within five miles of it, call the local tower and ask permission. In forty years we have not been refused. Johnny Mulder, who runs the company, holds an FAA commercial pilot certificate, which is why this answer is specific rather than vague.
Indoors and at shows
You need 15 feet of clear ceiling. Below that the blimp cannot sit above the crowd, which is the only reason to bring one inside.
At about one percent loss a day, a single fill comfortably covers a three-day show. Some exhibitors haul theirs inflated in a trailer between shows and roll it off ready to fly. Check the venue’s own helium rules before shipping.
More at usablimps.com.