I've had a bunch of people ask me how to make blogs wider and pictures bigger. Here are some links for you if you're interested:
To make your blog and header wider, go here.
There are a couple things you can do to make pictures bigger. First, you can upload them to photobucket the size you like (I'm liking my vertical ones to be at like a 550 pixel width, and horizontal to be around 600). Then copy the line under the picture that says "direct link." Then click the little picture icon at the top when you're composing a post (like if you're adding a picture from your computer) but instead of browsing and listing the pictures you want on the right side, paste in that "direct link" you copied from photobucket where it says "or add an image from the web" on the right. Does that make sense?
The second way is a little more technical. Click here to check it out.
Hope that helps!