I'd like to have two blogs, each about it's own topic. Am I allowed to have both blogs linked to the same AdSense account? And I just read that I have to have a actual website that's six months old in order to use AdSense on it? Is that true?
Yes, you can have both blogs linked to the same AdSense account. If you are existing adsense user, you can use your adsense on the website with less than 6 months old.
Yes.. You can put your adsense to as many sites as you can.. But, make sure that all the sites comply with the Adsense Policies.