Your eBook will not write itself, so make the time by scheduling appointments with yourself. Whether you work at another job or stay home to write and work online, sticking to a schedule is extremely important. Figure out what time of day is best for you, and plan to write for 30 to 60 minutes during each writing period.
Starting with an outline is the most important thing to get you started. Your outline will be the road map you can follow to make your eBook flow naturally and logically from beginning to end. Once you have outlined your eBook and divided it into chapters, you will be able to accomplish more during the time you have scheduled.