Blog style thumbnails

Hi I’m less than a day old to the wonderful world of WordPress I’m using the latest version….. I purchased a theme from organicthemes.com and would like to change the layout. at the moment my video post are one per column or line and I would like to have it as three video post per column, how can I achieve this ?/ what do i have to do to get my video post as three thumb nail post per column ?? please help !!