Yes. Continue to #6.
No. Consider whether an outline will help you get started. If it won’t, skip this step and go on to the next one. But realize that at some point, when querying an agent for a fiction book, you’ll need a synopsis, and for a nonfiction work, you’ll need a book proposal; a synopsis, summary, or overview; a detailed table of contents; an author bio; a comp title analysis showing what books are already in the market; an outline as well as the first few chapters for the book proposal. What each agent requires will differ, and you should review the requirements carefully before sending query letters.