Lending Club is a platform where you can lend your money to other people. You’re the bank. Each note is only $25, so you can invest $1,000 and lend money to 40 people. There are many grades of loan (from safest to riskiest) and investors earn, on average, between 5% and 7% annualized returns. For more information, check out Investing and Making Money with Lending Club Peer-to-Peer Lending and my real money Lending Club Portfolio.

Stock dividends: Some stocks, especially stocks from big corporate standouts, pay dividends to shareholders based on the number of shares they own, and the percentage of the stock price on the dividend date. For example, if a company pays out 3% on a stock that's trading at $100 per share, you'll earn $3 for every share of that stock you own. Add it up and that can be good take-home pay as a passive investment.

However, you should pick a niche and blog about that. If you're launching a money related blog, maybe it'll be about how to make money in real estate or simply how to make money online. Pick the niche and stick to it. If it's a diet and fitness related blog, maybe the niche is the Ketogenic diet, the Atkins diet or some other form of diet or fitness.
Investing in rental properties: Another form of real estate investment, rental investments (i.e. becoming a landlord) could steer you down the passive income path of steady monthly rent checks that you can use to pay off a mortgage loan on the rental property. After the mortgage is paid off, those monthly checks go right into your bank account -- potentially for years to come. 
In equity valuation, residual income represents an economic earnings stream and valuation method for estimating the intrinsic value of a company's common stock. The residual income valuation model values a company as the sum of book value and the present value of expected future residual income. Residual income attempts to measure economic profit, which is the profit remaining after the deduction of opportunity costs for all sources of capital.
Thanks for the great article…although I have to point out many of the items listed are not passive but active, such as selling bodily fluids, writing blogs or resumes, and collecting bottles and cans. To be truly passive, the income source must require no effort on your part (after initial setup). Real estate, dividends, P2P lending…these are truly passive income sources.
To create residual income, you need to create something that people will continue to buy on a regular basis long after you’ve created it. A house is a prime example of this as people will continue to pay rent for the right to live in the house. A business needs to have products that are sold over and over again rather than trading the business owner’s time for money.