@headcaseoutlet your site looks good, but I have to be frank; the header is not sharp. I

Claire

#infinite-handle span {
	background: #d1e7eb;
	border: 1px solid #9bb4b9;
	color: #537a82;
}
#infinite-handle span:before {
	color: #537a82;
}
#infinite-handle span:hover:before {
	color: #f51909;
}

@headcaseoutlet it looks like your header is displaying at the correct non-stretched size -- 580px wide with a flexible height.

I want to replace each sidebar category title on my blog with an image.

You can use an image replacement like this:

#blog_subscription-3 .widget-title {
	background: url(http://s.wordpress.org/about/images/logos/wordpress-logo-32-blue.png) 15px 0 no-repeat;
	display: block;
	width: 36px;
	height: 36px;
	text-alignment: left;
	text-indent: -9999px;
	border: 0;
}

Note that you need to look in the page source code to see which selectors to use. In this example, "#blog_subscription-3" refers to the first widget in your sidebar. Each widget gets a unique ID after it is added.

I used a WordPress logo as an example image. To use a different image, replace the url() value with an image from your media library and adjust the width and height for your image.

I checked http://petitecuisine.wordpress.com/ and I don't see a "Load more posts" button there right now. If you still need help, can you reply with a link where we can see the button you're trying to change?

Is it possible to use a font not listed in my theme appearance page for the menu and side bar with the CSS upgrade and if so could you help me out with how to make this happen?

Sure! Check out this page about font stacks first:
http://unitinteractive.com/blog/2008/06/26/better-css-font-stacks/

Here is an example showing how to change the fonts for the menu and sidebar in the Forever theme:

#access a,
#secondary .widget-title,
#secondary {
	font-family: Georgia, Palatino,” Palatino Linotype”, Times, “Times New Roman”, serif;
}

Note that it's possible text for some things you add may have more specific selectors. If you find an example, you just need to examine it in the page's source view in your browser, determine the selector, and add that selector to the example above.

The answer is yes but it’s important to know that regardless which fonts you may wish to choose to jazz up your blog with, your browser and your visitors’ browsers can only use the fonts installed in the same computer. If a reader does not have a specific font installed on his / her computer, the browser will determine which font is displayed.

Just to clarify, the above is only true if you use a font stack via CSS—the Custom Fonts are loaded (and licensed properly) via the web and each reader's computer doesn't need to have the font installed in order for it to show up.

(Just posting this to make sure people coming back to read this later don't get confused about the differences.)

Is it possible to pick which photo from each post is used in this grid?

No it is not possible. What is possible is stated in this guide http://en.support.wordpress.com/widgets/top-posts-widget/

Claire
Blog url: http://petitecuisine.wordpress.com/

The answer is yes but it’s important to know that regardless which fonts you may wish to choose to jazz up your blog with, your browser and your visitors’ browsers can only use the fonts installed in the same computer. If a reader does not have a specific font installed on his / her computer, the browser will determine which font is displayed. There are a very limited number of fonts (in English/Western languages) which are common for most operating systems/computers/browsers.

#access a {
font-size: 100%;
}

Just increase the 100% to your desired size.

Any suggestions about increasing the font size for my menu?

#image-8, #image-9, #image-10, #image-11 {
margin-bottom: -8px !important;
}