First off, it is very slow to earn bitcoin without freelancing or buying it. If you want to try, here ya go!
1: Faucets (why bother)
Faucets are websites that give away very very small amounts of bitcoin or other cryptocurrencies free. The do this by paying users a portion of ad revenue from thier site. Just google "Bitcoin Faucet" to find some. This is almost never worth it though.
2: Read Books
You can earn money by reading books. This website is basically a bitcoin faucet, but a little more fun. The website is http://www.paidbooks.com
3: Free Dice Faucets
These are essentially all faucets, so I'll just keep going. Most dice sites will give a small amount of bitcoin that you can gamble with. Do not use these sites if you are under 18, as they are gambling. A popular dice site is https://primedice.com
4: Work For Them (Best way)
You can earn them by working for them. Not a lot to explain, so I'll just list some sites.
http://coinworker.com/
http://www.reddit.com/r/Jobs4bitcoins
http://xbtfreelancer.com/
If you have any questions just comment them!