When you're talking about just having bitcoins then the best source of bitcoin is an exchange with money, real money. When you're talking about having zero starting money, you could start earning by typing of captchas, signature campaigns, trading, gambling. It is a great source of bitcoins
It may be little but it is really a good place to start with. Ignore the face value and get some little bit of btc to start off with and see how it can be stored in your offline wallet and what can it do. When you have more experience den you may use your currency to exchange for it.