1) Make a list of your skills, interests, experiences, hobbies and passions. All the most successful home based business owners I know have tapped into their passions or experiences in starting their business.
2) Research to figure out how you can turn your experiences and interests into a skill, product or knowledge you can sell. For example, if you like gardening you can start a home-based landscaping business, sell gardening tools online, or start a gardening blog.
3) Test drive your home business before you go full throttle. Sometimes a business idea can look great in theory, but be tedious in reality. My sister wanted to do medical transcription from home, but after one day of typing, she realized it wasn't for her. Starting your business part-time on the side allows you to try out the business without a big commitment and discover if it's really as great as you think it will be.
Here are some great resources for further information on finding the best home business for you:
How To Select a Home Business Idea: This article guides you through an exercise to brainstorm home business ideas that you'll love.
Home Business Ideas: Check out all the different types of business you can start to see if one piques your interest.
Start A Business Part Time: Outlines the advantages of moonlighting with a home based business before going full time