How to change posts to have poster info on left

[is mise]

Very simple question. Most vB sites (including this one) seem to have information about the poster of a message over in a column on the left, rather than a row at the top of the message (as in my default installation).

I'm a total noob in terms of vB. How do I change this? I looked at the admincp section on Style Manager and didn't see anything obvious.

Is this a preference or do I need to install something or what?

Thanks!