Advertising

Google, my blog's sponsor, has an advertising program. It's where their money comes from, after all. And they're good at it.
I think I would like to advertise my blog. Two problems. One, financing, which I think I'll take care of reasonably soon.
But two, and probably more important, is keyword decisions. I literally have no idea what people want. Analytics tells me that people's favorite article is the philosophy one, and I can hardly claim to be a philosophy blog.
I could have a banner. Except I'm terrible at drawing. So this would amount to paying someone else to draw a banner, which would be more expensive.
And where? On certain search results? On similar blogs? Something else that I haven't thought of?
Marketing's hard. How do you convince people of things, most importantly paying attention to you in the first place?
Google, can you have a "suggest advertising" program of some kind, that maybe people pay for or something?