As a small business owner, you are more than likely to be your only employee when you start off. So, your income will be directly related the the time you put in. There are only 24 hours in the day and you need to get the most out of what you put in.
A friend of mine makes and sells handmade baby slings. She kept things as simple as possible. She didn't have an ecommerce website, she didn't accept credit cards, she used hand written receipts and her client contact list was on an excel spreadsheet.
1. A phone order comes in: Spends a 30-60 min. playing phone tag and taking the order.
2. The customer sends a cheque in the mail: Spends another hour having to drive to the bank to deposit it.
3. Product needs to be shipped: Wastes 30 min. to call UPS or Canada Post, sit on hold and wait for a quote.
4. Fills out receipt: 15 minutes to fill in all of the standard info in her receipt book.
5. Add Client to contacts database: 40 min finding that Excel file to recopy all of the information that she just wrote down on the receipt.
In the end, she has just added another 3-4 hours to just one sale. For her to make that back, she has to take on another $50 to her final price. And that's if she just wants to make minimum wage!
What I am getting at is having the right tools that automate as much of the process for you. I am not suggesting that you run our as buy all the software you can and throw it at the problem. I have been guilty of that in years past. What ended up happening is that the software became more of a hassle than the pen-and-paper method, so I didn't really use them. Also having one piece of software for my website, a different one for my invoicing/billing and another to do my contact management, meant that i spent a whole bunch of extra time copying or migrating data between the systems. Not the most efficient use of my time.
Most of you just starting your business, might think that an investment in software might be too expensive, but i assure you the cost will pay for itself; in your time and your sanity. A properly developed Drupal website can handle all of this for you and then some. Drupal has enough modules that it can be more than just a website, it can help manage your business.