To be a successful freelance you need the perfect way to communicate with people and you need the perfect tool to do your job.
The best communication tool is definitely Google. Nothing beats the power of Gmail or Google Chat and Google Plus. Informing your clients about what is happening with you is a piece of cake.
Now, back to work.
If you are a writer you need the perfect search engine and also the Google Custom Search engine to search just the sites that give you the best information possible in the shortest amount of time possible. The best sites to search are those who are private (meaning articles are manually approved) and those that almost no one can write to.
If you work with design or projects management or anything else, just find the best tool using Google Custom Search. Forget about non free sites because they just want to sell things.
Finally you will need a lot of experience so i recommend you to start working right now first as an amateur and only then as a professional.
It is possible to make a living online with freelancing but it is not possible to make a living if you are an amateur. Learn the difference between professional and amateur.