width content/ frame around sidebar

Hello, I would like to adjust my website, as I think there is too much white at both sides of my website: http://analiciafortes.com/. How can I make the content area wider? Secondly, I would like to have a thin line under "About me/ (over mij in dutch) "in the sidebar area. How can I create this? The line should be black and as wide as the picture beneath it. Then, I would also like to have a black frame/line around the sidebar area, so that the sidebar area is a box. How can I create this?