|P is for Practical|
I'm not a consultant, but I have looked into it, and do have a few friends and family members who have formed corporations.
If I were going to do any work for pay for someone else, outside of an employee/employer relationship, I would definitely want a corporation to protect me from liability. Any tax or other benefits would just be gravy.
Most of my friends and relatives have formed S Corporations. I've also see the term LLC, but S-Corp seems to be the overwhelmingly popular choice from what I've seen.
As for salary, my father (a consultant after dissolving his software company) always paid himself a small salary, had the corporation pay for everything that could be validly considered a 'perk' or legitimate expense, and got the rest of the money he made through the corp . . . Through some other means; sorry I can't give you more info or details there
Everyone I know has a lawyer and an accountant to keep them straight with Johnny Law. It's expensive, but an hour of a lawyer's time costs less than hiring one for a tax fraud trial. I think the states and the IRS are lenient and good about payment plans and such if you're a small business owner or consultant who, without malice, made a legitimate mistake, but I'd still want a professional to make sure I did everything by the book.
Everyone I know has an accountant, but they do more than one or two gigs per year. I'm nor sure if it would be easier for a DIY tax preparer to do their own taxes if they only did a few jobs per year. But I would want the accountant to make sure you understood all the laws and regulations. Heck, I have a very simple tax situation and I still get confused sometimes when I try to itemize.
EDIT: The SBA might be of help, as well. See if these pages help: