Once you've sufficiently protected your company's assets and hired a few key people to help you, it's time to focus on writing your business plan. My biggest piece of advice is not to rush into the writing of the plan.
Many people start typing before they've finished thinking.
They wind up with a convoluted plan that requires major revisions. What they think your company does. What the company needs in terms of money, people, technology, alliances and so on to grow. Your company's strengths and weaknesses, specifically, how the company can make money and when. What market your company's in, and how it stacks up against competitors.