#header-image {
	width: 100%;
	text-align: center;
}

Or to change out the header image to a different one, first upload a 1200 x 200 pixel image to your media library and copy the image URL, then replace the url() value in the example below with your uploaded image.

#header-image img {
	display: none;
}

#header-image {
	width: 1200px;
	height: 200px;
	background: url(http://fencingtime.files.wordpress.com/2012/04/cropped-6793288022_2b6a78da1b_b.jpg);
}

Thanks!
Jen

If you change your #wrap width to 1200px, you will make your entire blog wider. This introduces problems with centering that you'll have to fiddle with to fix, but it's a start. Keep in mind the average width of screens for your readers, and you may introduce a horizontal scroll bar if you make your content too wide.

You will have to either make a wider header image or center it. That is your #header-image id.

If you increase your #c2 width to 940px then your fill up the remaining space with your main content.

I know this isn't exactly what you asked, but you may want to start there for figuring out how you want it to look overall, and then you can work on your margins and padding to align it how you would like.

Good luck!
-Z

I was able to make my main column wider to the right, and I made my right sidebar smaller to fit. Yay! What I now want to do is make it wider on the left. Here's the code I have now:

#c2 {
background:#fff;
border:solid 4px #d2d2d2;
border-left:0;
border-right:0;
float:left;
line-height:170%;
margin:0 5px 0 0;
overflow:hidden;
padding:0 30px 30px;
width:700px;
}

#c3 {
border:solid 4px #d2d2d2;
border-left:0;
border-right:0;
float:left;
overflow:hidden;
width:195px;
}

I appreciate any help. Thanks!

Please be patient while waiting for CSS editing help.

That is of course just my opinion as a web designer, so here you go.

.col-full {
width: 1400px;
}

#main.col-left {
width: 1180px;
}

In the "maximum width for video/image field down below the CSS edit window, make sure and increase that number by 460px. Also, you will have to delete all the images from all of your posts and pages and reinsert them after making these changes.

I'd like to make my posts wider. How can I change it?

Thank you!

.one-column #page {
max-width: 690px;
}

After increasing the width, increase the width for images and videos in the field below the CSS edit window by the same amount so that when inserting image into posts or pages, they will come in at the larger size. Example: max-width increased by 100 from 690 to 790px, increase the number in the field below the CSS edit window by 100px also.

Also, please go to settings > reading and set your site to show at most 3 posts per page. It takes absolutely forever for your site to load because you use so many images and those of us on a slower internet connection will not want to wait around for 2 minutes for your site to load.

1. You can set the header image up so that it will resize, but that means that when the browser window is set really wide, the image will lose quality and look bad.

2. If you set the image to a static size, then when you have the browser really wide, the image looks like a tiny clown hat on top of your pages.

3. If you size the header image really wide, then when the browser window is narrow, much of the header image is missing.

The reason their is a maximum width set in the newer semi-flexible width themes is partially to keep the header image issues I've mentioned from being an issue.

If you haven't paid for the upgrade yet you can click Preview to see how it would look although you might have to force refresh the page once it loads for the change to become apparent as many browesers load in the old cached styles and forget to add the new ones.

If you do change the width of your blog you'll need to create a new, wider header image and add that with CSS too.