If all you're needing is a simple bar chart for your website, check out this new tutorial from AnyExample.com. It provides a simple, one function method to creating the image.
This article contains PHP function ae_bar_html for generating HTML/CSS based one-column bar charts. It is suitable for simple diagrams and does not require libgd.
The function takes in the values, the default height of the tallest bar, the colors to make the bars and the width of each of the columns. As a variation, they also provide a CSS-based version (versus just the standard HTML) and include examples of it in use.