I have started creating websites 12 years ago, and monetise them with adsense since 2005. I was a Software engineer but bored with coding and joined the "Web Master World". Most of my advice comes from my experience in UK market and few niche but you can use it in US and other markets. Set yourself a goal/target. If you have no destination then it does not matter which way you go(alice in the wonderland). My target was $1000 per day , nearly got it but few months later Penguin update slapped me Anyways, you have to have your clear goal, say $500 month, or $100 a day. Something that you can believe that you could achive. Find your niche. Find a subject that you can enjoy creating sites about. But keep in mind that if no one advertising on that subject then you cannot make money. On the other hand if "MESOTHELIOMA LAW FIRM" (pays +$20 per click) is your passion, don't lie to yourself well, you wouldn't enjoy this subject would you? I am in Travel and Car insurance niche and earning well. Unique content, Update regularly and try to get Search engines to love your sites. Do not listen "make sites for people not for search engines" crap. If no one visits your "Made for visitors" site you cannot make any money but if your site on first page of google then everyone going to love your site as soon as decent content and info is there. This is a unique tip for USA markets especially: for beginning try to rank on bing and yahoo, because in USA still %30 of search done outside of google. Google is complex and unpredictable for SEO you can loose all your efforts in next algorithm update. But Bing-yahoo still old-school reliable search engines with predictable results. After some income and success you can go to Google's Arena. Do not give up! Patience is the key of success on Adsense business. Rankings does not come overnight but once you are there, you can enjoy taking breaks and come back, once I left my sites for 7-8 months with 1-2 hours of work per week done by my assistant and took a long holiday with income.
M Maybe it's because I've been around so long. I guess these words of advice are for very, very new people at this that are to lazy to just use the search bar. But these are things everyone already knows!!! Your post can't get more noob friendly than this.