Blog post layout and design

In 7.1, I'm setting up a new blog.

I want to do two very simple things--have a 2 column text layout, and have a smaller centered image. No doubt, these are simple, but if someone could suggest an info link (so far, I haven't found information on this), it'd be appreciated. I've only been able to make 1 column posts. 

In general, is there no way to really design blog posts in a specific personalized way?

Thank you.