When is the time where a blog (hosted in blogspot) will be considered Adsense ready? How old should a blog be? Are there any required stuff besides age?
I monetize from the very first day. On those days when I used traffic exchange, I took off the Google Adsense.
It's against the TOS of Google Adsense to use traffic exchanges. That is why I need to take Google Adsense off. However, I gain a few subscribers to my blogs from traffic exchanges. In a sense, it's worthwhile to use traffic exchanges for a couple of weeks until the traffic from search engines comes.
It's really kind of worthless to put adsense on your website in the beginning anyhow because you are not going to make a lot. Build a quality blog, get a lot of keywords, and write about stuff people are interested in. Then, insert and/or worry about the adsense.