Any blog topics will do as long as you are familiar with the topics. Of course no Adults or Gambling contents. Once you start you blog, put in more effort on creating contents for your blog and link building. You will see results if you do these consistently for long term.
I suggest you make a blog on the topic in which you have the most interest. It is because, that way you will be able to add good, useful and informative content in the blog. Anyway, here is a list of high paying keywords but I am not sure how accurate this dta is: forums.digitalpoint.com/showthread.php?t=783358
The knowledge is not important, you need only these things things: 1. Good seo template 2. Profitable niche... shhh 3. Good amount of coffee and redbul And then submit and quality unique content!
Oh I almost forgot, Remember that building blogs specifically for Adsense breaks the Adsense TOS. Your primary goal should not be to make a blog only for the adsense ads. You have to add some value to the readers.
One thing you want to say away from is Tech. I have heard the per click payouts are garbage compared to others.
If you are seriously about making money from adsense, you may need to learn the topic that you are going to blog, in case you don't have knowledge on some paying keywords.
content is god.. google loves content. if your content is unique and with the right SEO and website promote. you will be earning money from adsense.. good luck
Here's the scenario. You're going to bust your balls on niches like forex, seduction, diet, and other supposedly high-interest, big-ticket niches. it will go either of two ways: you're one of those guys who makes the big-time niches work...or not. If not, then just gravitate to whatever niche you REALLY care about. Left-handed chess or underwater bagpipe playing. and then you'll find, miraculously, that there is a market (though small) for blogs about underwater bagpipe playing, and you will dominate the market.
Make a blog about Forex. That will bring you some good money. Go and steal some content, rewrite it, post 100 posts, build 200 good backlinks and you will earn like 10$ a day.