Multiple Streams of Income is chock full of advice. The investing advice is also great and certaintly better than what you will find say in JBQ's ridiculous book which cost many people millions in lost dollars. I saw a review here by Mr. Donoghue. My guess is that some people will try to bury that untill mindless 1 star reviews. If you can scroll back and read it, I highly recommend that you do. It shows a system of investing that yielded huge returns even during the Clinton "bear market."
If you want to top up your income without taking on a strenuous second job, your first port of call should be your very own skillset. If you have a natural talent that could help others, you have an instant “in” to easy money. Whether you’re a gifted guitarist, mathematical genius or speak a second language, almost any talent can be turned into cash. Offering one-to-one coaching is a flexible way to make a solid hourly rate, and enables you to take on as much or as little work as you wish. Find local clients by placing adverts in the library, schools and community bulletin boards and share your talent in exchange for a fee.

Attributable to compensation for services performed in Connecticut or income from a business, trade, profession, or occupation carried on in Connecticut (including income derived directly or indirectly by athletes, entertainers, or performing artists from closed-circuit and cable television transmissions of irregularly scheduled events if such transmissions are received or exhibited within Connecticut);
There are dozens of ways to generate passive income. However, the option you select has to do with two metrics: time and money. Either you have a lot of time or a lot of money. Most people usually don't have both. But, if you have a lot of money, generating passive income almost instantly is easy. You can buy up some real estate and begin enjoying rental income. Or, you can invest in a dividend fund or some other investment vehicle that will begin generating a steady income for you.

Petroleum products and chemicals are a major contributor to India's industrial GDP, and together they contribute over 34% of its export earnings. India hosts many oil refinery and petrochemical operations, including the world's largest refinery complex in Jamnagar that processes 1.24 million barrels of crude per day.[171] By volume, the Indian chemical industry was the third-largest producer in Asia, and contributed 5% of the country's GDP. India is one of the five-largest producers of agrochemicals, polymers and plastics, dyes and various organic and inorganic chemicals.[172] Despite being a large producer and exporter, India is a net importer of chemicals due to domestic demands.[173]
Ancillary Activity Test - The nonresident’s presence in Connecticut is ancillary to his or her primary business or employment duties that are performed at a base of operations outside of Connecticut. Ancillary activities are those activities that are secondary to the individual’s primary out-of-state duties, and include such things as presence in the state for planning, training, attendance at conferences or symposia, etc.
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 focusing on your wealth management goals, investment income is obviously critical but you might fund your goals from wider sources of income.  A typical long-term portfolio might produce about half its return as income and the other half as capital growth, though in times of duress the capital growth component wanes.  In this low-interest rate climate, some sources of income have become quite expensive and may prove disappointing against your spending needs.  But by tax efficiently and sustainably drawing income from wider sources, you might meet your goals while more prudently balancing risk against reward.