Well you need to learn seo afiliate market and traffic generating methods It's hard is no easy if it was evrybody would do it ...
In short, you just need one website/blog. Then, be consistent to add unique content with good keyword/phrase onto it, build backlinks and promote, promote and promote. You may take more than 1 year to see good results/return. Don't give up and keep up all the hard work and you will see your site's earning are growing. It is all about consistency of hard work. To the Best to you!
Find a good niche theme, create a good quality site and put in a lot of hours marketing your site and yes you can reach your goal. Fact is that it's going to take a lot of work to make that kind of money using Adsense.
no i'd say more than 2+ years solid contenet it need so much efforts and work, it's not an easy task ... but nothing impossible, google, yahoo, facebook all started from simple ideas... i beleive Internet is about new ideas now, it's not easy as before but yet new ideas are the way to go....
all you need is content, ads placement and a good quality traffic. its how you promote your website and do SEo that will let you earn huge income in adsense..