When do I formalize my idea into a corporate entity?

I’m a programmer with an Idea. I have a working demo. I have the funds to cover hardware, bandwidth, software development cost, ect. I am currently doing most of the development myself, using Odesk hires, and hiring friends for contract work, with no formal contracts.

*When do I need to get formal with a corporate structure?*
Is it really necessary to incorporate?
Or, can I keep track of the important paper work for taxes etc., myself?
Is there such a thing as a part-time business lawyer?
Who else do I need to hire right away to help me with these processes?
Should I use my first employee to fufill these business “process” needs?

_Please submist your suggested answers or advice as comments to this story._

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.