plan plan plan
I know you asked about info from the pilots point of view but if you can keep the below list in mind, that is aimed at the photographer, then it will make your life easier as the pilot.
*Local pilot knowledge invaluable regarding control zones, air traffic issues or delays, noise issues ect.
*Ground recce is useful if is an important job. Look for nearby buildings that could be noise sensitive at the time you are flying.
*refer to Google earth images of the area
*Google for images of the subject if it is well known landmark.
*Consider prevailing wind and direction of sun before deciding which door you will shoot from.
*High shutter speeds above 1/250th sec if possible.
*Kenyon gyron useful but not essential.
*Camera accessory bag that has a deep pocket or throat
*A few small D ring carabinas to secure camera accessory bag.
*Harness if are going to be leaning out.
*Electricians tape
*Thick long socks so you can tuck your trouser legs out of the way and they don't flap.
*Shooting schedule or shot list taped to back of seat. (but not on bulkhead of a jet ranger above 60 knots as it could be sucked out)
*I don't believe it prudent to have a camera safety strap if you are using more than one camera as it is too easy to get into a muddle.
*Practice opening and closing doors if appropriate.
*If working from the back and using both doors consider removing seat cushions.
*On the day, at least an hour to flight plan and get yourself comfortable.
*Try and have an arrangement where you can cancel on the day due to weather.
*If your point of departure is miles from the location and the weather is only occasionally sunny consider having a friend at the location to give you heads up of local weather as well as a set of eyes to warn of unforeseen problems.
*Consider the politics of the company that is employing you as they can be linked to any noise or low level flying complaints from the public. It wont be joe bloggs cameraman/photographer causing the noise it will be reported as a low flying helicopter from "X" company.
*If you are going to loiter over a large industrial complex for hours telephone them in advance to let them know you are working for them.
*Remind yourself that unless you have special insurance your mortgage and accident insurance does not cover accidents in light aircraft and charter company accident insurance generally only pays out if legal liability can be proved.
If you can achieve half from the above you will be in better shape than most!
Mickjoebill