How many ways for earning bitcoin

-Mining (I know nothing about it though but only know it has became impossible for the average Joe since 75% of mining is done in China where electricity is cheaper)

-Gambling/Sports betting (this kind of website > nitrogensports.eu)
-Affiliate programs: advertise a brand by posting your affiliate link (any service related to Bitcoin)

-Signature campaigns: the best way and easiest way in my opinion, get paid in Bitcoin by posting on this forum, keep an eye on this thread 

https://bitcointalk.org/index.php?topic=615953.0

-Trading: only recommended for experienced people with skills in trading, try first by placing "air" trades to see if you are competent or not

-Keep an eye on the Services section of the forum, you can do some small jobs like translations and get paid in Bitcoin
All the best