Remove Header from Posts / Expand Post Margins

Hi everyone –

I’m trying to expand the margins in my posts.
I’m hoping for my pictures to fill the space from left to right in the white area:
http://www.cindersphotography.com/blog/2013/09/01/pasadena-wedding/

Also – Any suggestions on getting rid of the header on my posts:
http://www.cindersphotography.com/blog/2011/07/09/nicole-and-bens-wedding/

Thank you!!