I've been working with beginning web developers for many years now, and the most common question I get is how to get images to display correctly. Images are challenging for the beginning web developer because they have to understand how web servers work (a little) and how directory systems differ on their home machine and their web server.
If you still are having trouble, you should consider signing up for my Free HTML class.
Centered alignment is a popular design element as it's relatively easy. In fact, now centering with CSS is arguably harder than it used to be with the CENTER element (that element is deprecated and you shouldn't use it). However, there are drawbacks to centered design. In fact, Jacci, the Desktop Publishing Guide, recommends that you should avoid centered text for most body copy.

Be sure to mouse near the top of the “beer” to see what happens. But if you're using Internet Explorer, you'll need to check it out in a different browser. All versions of IE are sent to their Feedburner page instead. There are some interesting choices for the sectioning tags in this document. For example, the dates in the posts are listed as
ASIDE and they might better be defined as
DATA elements with machine readable dates in an attribute. The images are also enclosed in a
SECTION element which appears to be there primarily for the CSS styles—he should use a
DIV instead. But it is a fun site design.
Have you built an HTML5 site? Or do you know of one that does a great job with HTML5? Submit HTML5 site designs to be featured on this site.
Buttons are a fun feature of web pages, but up until just recently, if you wanted your buttons to have any interesting features at all, you needed to use images. In fact, if you search the web for ”web buttons” you will find hundreds if not thousands of examples of buttons you can use for your web pages. But now, with CSS3 you can create buttons that have cool effects but don't use any images at all.
Read the full article to learn how: CSS3 Buttons (Note: there are four pages to the article, and page two shows you how to create the above buttons.)
Other Fun Things to Do With CSS