Index funds provide you with a way to invest in the stock market that is completely passive. For example, if you invest money in an index fund that is based on the S&P 500 Index, you will be invested in the general market, without having to concern yourself with choosing investments, rebalancing your portfolio, or knowing when to sell or buy individual companies. All that will be handled by the fund which will base the fund portfolio on the makeup of the underlying index.
If you know anything well, a place, how to fix something, how to make something, how to do something, you can write a guide for it. You can sell your guide as an e-book, offer it as a download for a fee on your site or reach out to bloggers with similar content and ask if they will offer it as a paid download on their website (for a price of course).
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.