So what are your goals? If you are hoping to make $100 - $200 more per month, then you can probably get by with a few hours per week of hands on activity in your business. I had a perfume business once that was averaging about $850 gross per month. After the initial time investment of the website, I was spending about 8 hours per week with various business activities (selling, shipping, advertising, accounting, taxes, etc.) Once a business is established, given the right product line, then this is probably reasonable.
If you are looking to make a $1000 or even more per week, then the rules can change drastically.
Understand your goals and look close at the time you have available to spend. If you only have a few hours a week to spend on the effort with an occasional vacation week you could devote to business development, then understand that it’s going to take you quite a bit longer to get things going, and you success will be limited. Since most people have full time jobs, that’s a direct hit of 8-10 hour plus drive time to the time you can be spending on your personal business. This is where Time Management becomes a critical factor in your ability to succeed or fail.