Use a scheduler like the Franklin or DayRunner personal planner, keep your client information in your scheduler and enter this with ink.  Since appointments are often cancelled or rescheduled, keep your timed appointments entered in pencil so changes in your planner are easily corrected.

Another management skill that is required is the financial management, knowing how to manage your income so you always have the funds to purchase supplies, plus saving towards purchases of software and hardware required to expand your business.  An easy method of determining how much should be considered your income and what portion should be retained by the business is to split the net profit 50/50.  While this might not be comforting in the initial stages of your business, it will keep you in good financial shape and prepared for future financial requirements.

The management of your business requires strong organizational skills and self-decipline, but once mastered this will repay you endlessly by eliminating the stressful situation of having to decline work because of lack of resources (financial and supplies), and permits you to maintain a balance between your business and personal life.