No matter what your business is, you need to pay close attention to regulatory details. You may find it hard to believe that your home-based eBay store or small-scale freelance writing workshop could be subject to federal and state laws governing employment, but probably it will be. A business plan consultant can help you identify which laws apply to your business model, but if you're unsure about how small business regulations apply to your business, your best bet to bypass the business plan consultant and study up at the source: the handbooks and guidelines propounded by the Small Business Administration (SBA) and the law-making bodies who govern small business. As any business plan consultant can tell you, making a regulatory mistake will injure your business far more seriously than will taking the time to ensure compliance in the first place.
Among the topics you may need to get a handle on (assuming they apply to your business model at all) are business licenses, certificates of occupancy, the status of your business' name, trademarks, patents, copyrights, tax information, federal "self employment" tax, business insurance, your sales tax number, unemployment insurance tax, health and safety issues, immigration issues, worker's compensation, bar coding for products sold, and minimum wage. While some of these topics are highly specific (you may never need a certificate of occupancy, for example, depending on how your business is run and situated), many of them are universal. At virtually no time, for example, can you obviate the federally-mandated minimum wage if you act as an employer to any other workers. Business plan consultants can factor these contingencies into your business plan when that information is required, but you should perform independent research to confirm that you are in full compliance with all applicable laws and regulations, both at the state and federal level, prior to entering business.
The list above, provided by the SBA and available for your perusal online, is not necessarily a complete catalogue; these are merely the most common requirements relating to permits and licenses that a small business start-up will face. Regulations and laws will vary by industry and by state, and they can evolve over time as modifications are enacted or ratified. It is important to define which specific agencies you will be dealing with in your industry (for example, if you work in construction, there are industry-specific OSHA laws that apply to your field operations). Beyond that, it is vital to ensure your compliance will all applicable terms and conditions of the law, as your failure to do so could leave you unprotected, trigger costly penalties, or even lead to the outright closure of your business.