If you're new to domain names, I suggest, imagine that a domain name is the equivalent of a piece of undeveloped land, except, your "raw" virtual property is on the web. Even better, today, so much more is possible! Exciting times! I suggest, the time to start is: now.
Much of what you'll read in this article goes against current popular thinking. A growing number of online affiliate-based businesses depend on third parties for income such as affiliations, Google AdSense, and so on. Yet if you're largely reliant on one or two sources for most of your income, sudden changes could put you out of business.