How to make money by blogging – First set up a blog then choose any good looking template for your site. After then write at least 50 to 70 articles on popular topics and share it on popular social networks and bookmarking websites. When your blog will start generating huge page views, you can monetize your articles with popular ad networks to show ads high paying relevant ads. Here I am linking some useful articles related to blogging, you can read these articles.
If you have huge followers on Twitter, you can earn money by promoting sponsored tweets. Read more about making money with Twitter.
If you want to make decent money online, I would suggest you to join at least 5 to 10 referral program which offer life time commission and then start promoting your referral links on the internet using your blog, social profiles, classified sites etc.