How can I earn money legally on the net?

Most online jobs are rip offs, you'll be getting paid pennies on the hour, most services are just taking surveys, watching ads or answering questions. However there is blogging and vlogging, if you set up a blogger.com account and are able to write articles with at least 300-500 words and it's original you could sign up for a google adsense account, Adsense pays you to post advertisements on your blog or youtube videos, keep in mind that you do need be original with your work, it can be difficult for your blog or vlog to get approved, but if you manage to succeed it would be one of the best ways to earn money online.

Another option would be to use your creativity to your advantage. There are sites that let you sell your artwork online, everything from portraits, landscapes etc. if you like photography and have a high quality HD camera you can sell stock photos online, you get paid per download and some people can make a very nice residual income doing it. Lastly, if you know how to create music you could sell your music on Amazon and Itunes, if you're successful you could make decent money doing it, but few people do. Which ever option you choose, just don't quit your day job.