There is no easy or quick money any where. You have to "Invest" either time or money or both.
Most on line business pays you for activity. Your own activity and for the activity of people you have invited through your link. Some also pay for different levels of indirect referrals in your team.
There are many sites which are asking you to pay and promote so more can contribute. The collection is redistributed using a system which may vary from business to business.
I prefer the ones which pays you for different levels of indirect referrals. The leveraging becomes much better.
Which ever business you choose, it should be genuine with a certain track record. I always recommend to join an established business to the beginners. Once you do make some income then you can go in for new start ups.
Net working businesses are mainly promotion businesses if you want to earn a reasonable amount. Don't get carried away by "It builds automatically or we shall build it for you". It doesn't happen. With due diligence you are joining a "Business" where you have to work and not a "Lottery" where you enroll and do nothing.
This means that you have to learn how to promote. Learning to use a "System", Traffic Exchanges, autoresponder, facebook, swom and other social sites connections etc.
To summarize... A genuine system, persistence, regular promotion and patience are what gets you results. I have recommended some genuine business in “On Line Business” and "Top Online Sites" Connect with me there and I can guide you and help you but I can not assure you that you will earn. It will TOTALLY DEPEND ON YOU.