Writing the Plan
Now that you know what goes into a successful business plan, all you have to do is write it. As daunting as that sounds, it isn't that difficult. The hardest part is just sitting down and getting started. Carve out a few hours of an evening or on the weekend, close the door, turn off the radio, and disconnect the telephone and the Internet. Concentrate on the task at hand, starting with a rough outline and filling in the details as if you were telling them to a friend. Take as much time as you need; a few hours, a few evenings, or a few weeks. Don't overthink it, just start writing and worry about editing later.
Once you have a rough draft down, re-read it as if you were a stranger to the story. Even better, give it to someone else to read and see if it tells them everything they need to know. See what questions they have, and incorporate these into any changes you need in your second draft.
After all the words are right, you can spend a few minutes making your document look pretty. Print it out, give it a final proofreading, and you're done. Then, and only then, you can start using the planto get your eBay business up and running.