Ok basically I'm a director I don't really pay to many people yet...but when I do need to pay someone couldn't I 'say' im sub contracting work out? Or do I have to incorporate my filming 'company' because cast/crew might not be consistant for each shoot?

I consider people that I hire to be sub-contracted. I take reciepts from each of them for tax purposes, and that's about it.

Incorporating your business is always a good idea due to the way income tax is structured. It should allow you to maximize your tax write offs vs. your personal income, but that's something you should talk to your accountant about.