Hi all,
I think this is one of the most asked questions about Joomla. Joomla by default sets all blog views into 1 leading article and under that 1 article it will start 2 columns.
Its really easy to change once you know where. This is done in the menu. So say you have a menu called "Blog" which is showing your articles in blog-style, go to the Joomla Administration > Menu > Your menu. You are now in the Menu item manager. Click on the menu item "Blog"
Then at the right side of that page under Parameters (Basic) you will find a little list. Change accordingly to your wishes. As you will be able to see, you can change 2 columns into 1 (or 3 if you like of-course). Click on the screenshot below for details:
[attachment=0:32fzuvpw]<!-- ia0 -->Menu Item_ [New].png<!-- ia0 -->[/attachment:32fzuvpw]
How to change the amount of columns is part of our 3 1/2 hour Joomla video tutorial available here:
http://www.joomtorial.com/shop