There's no substitute for doing your homework--START with chatting
with other helicopter folks in local area. Find out where the trouble
spots/agencies are, network through to pilots who've had problems, see
what you learn.

Government employees, generally, are likely to give you wrong answers
unless you work past receptionists & flunkies to the administrators,
by which point they've gathered so much information about your
proposed operations that you might have well published it in the
newspaper and you won't have a chance to keep it quiet should you want
to do so!

IF YOU'RE LUCKY the local agencies will say 'no problem.' But if
you're not, it could be that you'll wish you'd never picked up the
phone.

Basic regulatory structu landowner, constrained by neighbors,
severally constrained by town/city (if present), constrained by
County, then State, then Federal.

The most restrictive of these are town/city and Federal. I have yet
(in over a year of scenic touring western states with R22 on trailer)
to find a municipality that allowed helicopter ops within city limits
without multiple one-time permits & inspections & insurance hassles.
It's a cover-your-ass environment--"If we make it impossible for you,
we don't have to face irate voters!" Little city governments without
a policy in place listen to your inquiry, then immediately call their
buddies in BIG city departments down the road to find out what to do,
and the BIG city departments have already found out about voters, so
they pass the word, and suddenly the little city sounds just as
cumbersome as the BIG city. It's no accident. City governments are
bad news for helicopters!

Federal: BLM seldom CARES what you do, except for special cases.
(BLM-administered National Recreation Areas are mostly closed because
their role models are the NRA's administered by Nat'l Park
Service--no, no, a thousand times no!) USFS (Nat'l Forests) are
generically closed without special permits, I've been trying to get
one for over a year, they don't answer mail and universally try to get
me to go away if I call on telephone. [The problem is "recreational"
helicopters, they figure you have no NEED to be on USFS you can land
on adjacent private land! Commercial helicopter operations are much,
much easier to get permits for!]

Nat'l Park Service, Fish & Wildlife, Bureau Reclamation, Nat'l
Monuments under various agencies--all have basic restriction "NO"
without Act of Congress or equivalent.

Counties: pretty easy! Urban counties may be difficult, but others
seem to leave helicopters alone, deferring to local municipalities.
And, as with foot-launched aviation, "Tis more blessed to beg
forgiveness than to ask permission."

Sometimes it all gets weird: Lake Powell, Glen Canyon Recreation Area,
Page, Arizona: The NRA is administered by Natl Park Serv, NO you
can't land there. BUT BUT BUT the waters of the lake (160 miles long
.. . .) are OK for Watercraft . . . and for Seaplanes . . . and for
Helicopters! So with no paperwork at all, if you have a houseboat on
Lake Powell, you can operate your helicopter from it (outside of
marinas) as much as you want! The houseboat rental concessionaires
even offered to take down the shade cover on the upper deck of a
rented houseboat so I could use it as a landing pad! What a way to
spend a summer.