Most people like to try before they buy, so we rent out machines and masks, usually for a month prior to the purchase of the machine.
We generally try to keep masks minimal in size and bulk. People who sleep with their mouth open without CPAP will tend to breathe through their nose when using CPAP. We prefer to use nasal masks as leaks tend to be less, comfort more and pressures required can be less.
In order to have more of an idea of what CPAP involves and what you might like to try work your way through the following links:
ResMed CPAP Machine Setup Videos
Philips Respironics CPAP Machine Setup Video
Mask and Machine Cleaning Videos
Humidifier Tub and Tubing Cleaning Instructions