how to i adjust the column widths?

Hi everyone. My website is http://www.swimbikerun.ph

I’m having trouble with the alignment of my 3 columns where i put in my posts.

If you’ll notice the jquery slider aboves width is set at the maximum allowed. the columns underneath it (local news, sbr feature, and training) is not proportional. i want to extend, if possible the width of the 3 columns under the slider/make it closer to the sidebar. how do i do this? also how do i adjust the middle part of the feature and training tab? sbr feature is taking up more space then the training section. causing the pictures to get resized. (the pictures dimensions are the same and i want it if possible to show up at the right size.

thanks so much guys hope you can help me