How to fix my blog

I finally decided to do a pretty back drop for my blog, but it seems too small. I chose the widest layout. What am I doing wrong? I want it all to blend and right now it looks like it is in three parts: the backdrop, the header, and the layout. Argh!!!! I want it all to fit and match my backdrop. Any advice please help me. This is my first attempt, but since I am not a patient woman, I am starting to give up. If anyone knows how to fix it, so my blog entries are more narrow and I can blend them in with my backdrop, then figure out how to make the header blend I am all ears.