There are a lot of differences between having a career and being an entrepreneur.  One of if not the critical difference is that as an entrepreneur, you need to wear a lot more hats than you do as an employee.  A lot depends on what your career happens to be, but in many cases, starting a business requires that you either be an expert in many things that you did not do as an employee, or you need to hire employees or contractors to handle situations outside of your comfort zone.

A great resource to help you learn some of the things that are not on your resume is by taking an online course to close your knowledge gap.  Some of the most popular courses available at Coursera for the entrepreneur are:

Essentials of Entrepreneurship: Thinking & Action.  The purpose of this course is to provide the budding entrepreneur [or intrapreneur] with an understanding and knowledge of how to maximize your opportunity.  Some of the key topics that this course covers are: the importance of a business plan, business strategies for a new business, achieving success in a startup business and how to evaluate the opportunity, it's feasibility and how creativity is best valued.

When you have completed this course, you will be able to explain the business planning process, you will better understand the entire entrepreneurship process, and most importantly, how to recognize an opportunity and how to generate and assess your business ideas to attack that opportunity.  The instructor is David Standen and offered by the University of California at Irvine and should take between 4 and 8 hours to complete between the videos, readings and quizzes.

How to Finance and Grow Your Startup - Without a VC.  One of the most searched subjects relating to starting a new business is focused on different ways of financing your business for growth.  Most companies need capital to either start or grow their business.  This course will introduce you to five different models where your customers will help fund your business.  The five models were used by well-known entrepreneurs like Bill Gates, Michael Dell and Richard Branson.

The majority of companies never get any funding from Angel Investors and Venture Capitalists in spite of the consensus in the entrepreneurial world that raising venture capital is your ticket to success and wealth.

The course, taught by John Mullins and is offered through the University of London and should take 22-35 total hours to complete over seven weeks (5 to 6 hours per week).

Developing Innovative Ideas for New Companies: The First Step in Entrepreneurship. The whole startup process is a big mystery to people that have never done it before.  The focus of this course is to help, both aspiring as well as active entrepreneurs, develop great ideas into a new business.  In this course, you will learn how to identify and analyze an opportunity, build a business model that will lead to better and more strategic decision making.

This course, taught by Dr. James Green, is offered by the University of Maryland and should take 10 hours to complete working a suggested 3-5 hours per week.  The course is the first course in a four-course program titled Entrepreneurship: Launching an Innovative Business Specialization.

Entrepreneurship: Launching an Innovative Business Specialization.  One of the most critical aspects of entrepreneurship is focused on the mindset of the entrepreneur.  This course examines this mindset as well as the set of skills you will need for success; it will provide you with insight on how to spot an opportunity and most importantly, how to bring innovations to market as well as how to both establish and maintain a competitive advantage in your business.  There is a focus in the course of different financing and capital structures for new ventures as well as topics on how to raise external funding for both early as well as late-stage startups.

This course taught by Dr. James Green, Dr. Thomas Mierzwa, and Michael Pratt is offered through the University of Maryland.  This course is a little longer than some of the other courses and will take you about three months to complete, working 6 hours per week.

Design Thinking for Innovation.  Business today requires that entrepreneurs, global corporations, and government entities do more with less.  The best way to accomplish this is to change the way that you are thinking.  Understanding modern design thinking is a great way to achieve this.  This course provides an overview of design thinking and how to employ this method of thinking as a fundamental approach in solving business problems.  The course relies heavily on several case studies to illustrate and understand this process.

This course taught by Jeanne Liedtka is offered through the University of Virginia.  The course should take 10-15 hours to complete over five weeks, with 1-3 hours of study per week.