Lots of websites offer a few day turn-around if you're willing to spend $300... It also depends how complex a corporation you want to start, and how many decisions you have to make (which state, which type, how many shares, etc. )

I've only had experience with incorporating a nonprofit, so maybe its different, but i think you have to go through your state's business portal (in CA, you go here http://www.ss.ca.gov/business/bpd_forms.htm) and first formally request the name, which takes some time, and then go through the rest of the process - drafting articles of incorporation and bylaws often takes more time to agree upon than you think. i'd say atleast a couple weeks. but i am no expert.

IANAA, but I heard from an accountant that a lawyer should be able to incorporate you in a few days - a week. I have no firsthand experience with this, however.

It depends on your longterm goal honestly. Usually the best thing to do if you are simply trying to start a business is pay $25 dollars at your city and county builing and file LLC papers (Limited Liability Corporation).

Sorry..didnt finish the thought. An LLC is a cheaper alternative to trademarking a name or logo and works just the same. An LLC protects your private assets in cases of lawsuit or insurance.

About a year.