This not a simple question, but there are lots of simple answers.
I would say your best bet is to paste the same question into the search box at the top right next the search box that says hubs and then click search and start reading the list of hubs that appear. You will start to read of new terms that you may not have heard before, but will help to fine tune your earning knowledge.
Advice - get a notebook - it helps with recording topics you wnat to search more on.
Tip - everything you need to know is right here in hubs written by hubbers as they progress in earning experience and share hteir findings about making money.