There are Hundreds of Ways to Earn Money Online. You dont need to have second job if you want to earn money online. I have listed out some best ways to earn money.
1) Blogging, you can earn money by adsense. You can earn a lot with adsense.
2) Pay per click - You can earn money from pay per click sites.
3) Product Writing - You can write a product of your own and sell the product, which is very easy part, and earn money
4) Freelance Works - You can earn money from doing freelancing jobs. You just need to write articles or do link development or build traffic
5) Writing Reviews and Getting Paid - Perhaps, you write reviews for a product, and get paid money for each review you write.
6) Earn Money from Surveys - You can perhaps make lot of money from surveys.