Installation involves cutting a hole for the fan in the bathroom ceiling, mounting the fan to the attic trusses, cutting a hole in the roof, and running a vent line to that hole and the outside cover. Do not vent any fan directly to the attic. Installation only requires some minimal carpentry skills. The difficulty is the installation of the required electrical line. While there are a number of places in the attic from which you can tap into an existing circuit, the problem comes when you try to run the switch down into the wall because of the way the wall is framed.
Professional help is a good thing here.
If you want a fan with a heater, or you want a wall heater in the bathroom, you will need to run a new circuit. Wiring for the upstairs or main floor of a Virginia Hills house was originally only two 15 amp circuits. One controlled the overhead lights and receptacles in the back half of the house and the other controlled the same for the front half. This isn't sufficient for today's electrical demands, and any electric heating will seriously overtax the existing circuits. I'm quite fond of the original Virginia Hills sinks, but if you don't like yours, or it's cracked and chipped, you'll want to replace it.