The FTC Business Center has a hub dedicated to protecting small businesses, information on marketing & advertising, and some legal resources.
The SEC has a page dedicated to small businesses and additional resources that help ensure you remain compliant.
The U.S. Small Business Administration can be used to find things like:
The N.C. Secretary of State's website has information on business registration, a tutorial video showing how to register your business, and a link to register your business online. They have a small video library with other useful tutorial videos.
How—and Why—You Should Trademark Your Business
The U.S. Patent and Trademark Office, as its namesake denotes, has information on filing patents, trademarks, and has a learning center to help users get the information they need in regards to both.