Actually, i am also new to DP but whatever i know about the adsense till now is that you have to increase your visitors, if your site is having a 100 visitors a day then the possibility of earning through the adsense is granted for sure, because i have one blog which having more 100 visitors a day and from this i got atleast 2 to 3 clicks per day, so in total per months i earn $60 to $100. For this i suggest you increase the visitors by joining some relevant community.
yep content is king, closely followed by traffic article marketing works, write some unique articles for your niche and submit them to ezine articles - this builds string backlinks and over time generates traffic. It's not easy but 100% works if you keep at it!
The more unique your content is the more traffic you drive the more chance your adsense earnings will be higher try and base your keywords around your content for high paying keywords