Starting a blog with AdSense - your ideas?

[NBG]

Hi,

i would like to start a blog about [niche here] and put some banners (AdSense) on it.

I have several passions/hobbies to write about but:

a) it's all said in a few posts
b) the target audiences is small
c) i'm not sure if they even search for it
d) perhaps AdSense shows irrelevant ads on the blog (and with low cpc)

So i'm looking for the total opposite:

a) enough niche-news to write about
b) big audience
c) many search requests
d) AdSense ads that fit to the content, tempt the users to click, good cpc

Any ideas or suggestions? Please no "promote clickbank products"

Thanks,
NBG