I found a way (by blog stalking) to change the fonts both in your posts, and your titles! I opted to just change the titles because I REALLY didn't want to deal with the rest. =) But this tutorial to change your Blog post, dates, and side bar title fonts. And you can check out this site to check out other tutorials to customize your blog even more! Changing the blog titles seemed like a lot of work when I first looked at it, but it's really easy once you start.
If you have any questions, you can send a note to the woman who does all the tutorials, or you can ask me about the basics.