If retirement is a goal of yours (and who doesn’t want to retire someday?!?), it’s important to learn how to start investing. In fact, funding your retirement accounts should be at the top of your list. While these accounts won’t help your immediate situation, by stashing cash now, the residual income they create should help propel you through your golden years.
3. Start as soon as possible. Building a livable passive-income stream takes a tremendously long time, largely because of declining interest rates since the late 1980s. Gone are the days of making a 5%-plus return on a short-term CD or savings account. Today, the best 12-month CD is at 2.5%, and the best money-market rate is about 1.85%, which is not bad, considering such rates were below 0.5% just a couple of years ago. Know that every $100 you save can generate at least $2.5 in passive income.
Part of providing value is building trust. Don’t link to things that aren’t of good quality or people won’t trust your recommendations. The other part of making an audience is consistency. It matters less how often you post than how consistently. If you only have time to do one post a month, that post should come out on the same date and time each month.

Anthony, nice setup! To your question about the rental mortgages, you haven’t said what interest rate you are paying. As a start, if you are paying more than the risk free rate (Treasury bills) which you probably are, then a true apples to apples comparison would be yes, pay off the mortgage. But, if you are comfortable taking more risk, you have other options to invest in which you *hope* will yield you more over the coming years. You also didn’t say whether the rentals generate net income and if so, how much? What is the implied rate of return on the equity you have invested in them? If you pay the mortgages off, you’ll have even more equity tied up, will the extra net income make that worthwhile? Maybe you should use the money to buy more rentals instead, if purchase opportunities still exist in your town. … this is less of an answer than a framework to analyze the decision, hope it is helpful.

But, you don't need to go further than that. You can simply write it and publish it and collect the income. That's all. Send out a couple emails to your list (if you have one) or post it on social media, and there you have it. Passive income. Now, the amount of income you receive depends on the quality of the book you've written. How well did you craft the message? How targeted was the information to your audience? It counts.
Managerial accounting defines residual income in a corporate setting as the amount of leftover operating profit after all costs of capital used to generate the revenues have been paid. It is also considered the company's net operating income or the amount of profit that exceed its required rate of return. Residual income is normally used to assess the performance of a capital investment, team, department or business unit.