I think blogging is one of the best ways for earning money online. Do you know what is blogging it's creating an online resource(blog) for any topic (here it's called niche) which people will find useful. If you are good at something (maybe you love to read books, to cook or anything!) then you can start a blog on that topic and make money out it.
Note: Don't expect to become the next Mashable in just two months, it will take time. Also, you have to understand and have deep knowledge of the topic to do blogging on that.
You can start doing blogging on Google Blogspot platform for free of cost, and nowadays it's super easy to create a blog (even a 8 class student can do it).
There are a hell of thing which you need to know about if you want to become a blogger. And seriously speaking i can't write all that here (I'm trying to keep this post as short as possible). But don't worry you can google everything you need.
