Add float or align selector for CCK image fields
Look into the Display Suite Module: http://drupal.org/project/ds

It is designed to give you more control of the display of your content from the Admin UI. There are links to detailed screencasts on the project page. You'll see versions for both D6 and D7.

I don't know if you get those options on the 'add new content' page, but it wouldn't surprise me if you did.