Before starting a home business, it is advisable to do a SWOT analysis of yourself (SWOT - Strength Weakness Opportunity Threat analysis). The reason you should do this is to determine if this is the right time to start a business. Take a piece of paper and list out your strengths and weaknesses. Check around to see what opportunities you have as well as what threats would face you should you decide to enter the business.
After you list out your strengths, try to find a partner/s who can complement you and cover your weaknesses. Find out from your strengths and passions/hobbies what is a workable business (i.e. a small home bakery if you are good at baking or freelance website designing if you are good Dreamweaver etc.) and than start doing a business plan.
When you do your business plan, it is important to keep track of your cashflow. Always make sure you have a positive cashflow else you will encounter problems later on.